Battle of Yongyu

The Battle of Yongyu (영유永柔 전투), also known as the Battle of the Apple Orchard or the Battle of Yongju by the Australians who fought in it, took place between 21 and 22 October 1950 during the United Nations Command (UNC) offensive into North Korea against the Korean People's Army (KPA) that had invaded South Korea during the Korean War. The battle was fought between the 3rd Battalion, Royal Australian Regiment (3 RAR) of the 27th British Commonwealth Brigade and the KPA 239th Regiment.

On 20 October, the US 187th Airborne Regimental Combat Team (187 RCT) staged a parachute assault at Sukchon and Sunchon, about 40 kilometres (25 mi) north of Pyongyang, with the objectives of cutting off KPA forces retreating ahead of the US Eighth Army general advance from the south, capturing important North Korean government officials evacuating Pyongyang, and liberating American prisoners of war (POWs) being moved out of Pyongyang. On 21 October, two 187th Airborne Infantry Regiment (187 ABN) combat teams started southwards in a reconnaissance-in-force to clear the Sukchon–Yongyu highway and rail line and to establish contact with the 27th British Commonwealth Brigade that was leading the Eighth Army advance northwards from Pyongyang. 187 ABN came under fire from the KPA 239th Regiment in the vicinity of Yongyu. As a result of the US airborne operation, the KPA 239th Regiment found itself caught between the Eighth Army advance and the 187 ABN attack in its rear. The KPA 239th Regiment attempted a breakout to the north just after midnight on 21–22 October. Facing determined attacks, the American paratroopers at Yongyu requested armoured assistance from the 27th British Commonwealth Brigade on the Pyongyang–Sukchon road just south of Yongyu.

The 27th British Commonwealth Brigade had departed from Pyongyang at noon on 21 October, headed north on the Sukchon highway, tasked with reaching the Chongchon River. The 1st Battalion, Argyll and Sutherland Highland Regiment (1 ASHR), leading the brigade advance, pushed up the highway until fired upon by KPA in the hills south of Yongyu. By nightfall, the hills were cleared by the Highlanders and the brigade halted for the night. The British could hear the sounds of a heavy battle taking place to the north. 3 RAR was directed to take the lead when the brigade moved out the following morning. C Company, 3 RAR, was selected to lead the Australian advance. C Company, with elements mounted on US tanks and the rest of the company following in motorised transport, was to pass through Yongyu as rapidly as possible and effect a relief of the 187 ABN defenders to the north. At first light on 22 October, 1 ASHR and the 1st Battalion, Middlesex Regiment (1 MR) advanced into Yongyu to clear the town of KPA. 3 RAR, with C Company on point, passed through 1 ASHR and 1 MR and moved through Yongyu, headed north on the Yongyu–Sukchon road.

C Company, 3 RAR, came under fire from a KPA 239th Regiment rearguard force entrenched in a hillside apple orchard north of Yongyu and aggressively counterattacked off the line of march into the orchard, routing the KPA from the high ground. The KPA 239th Regiment, now on open ground between 3 RAR and 187 ABN, was forced to withdraw westwards with heavy casualties. 3 RAR then relieved the American paratroopers in their defensive positions. By midday, after three hours of fighting, the battle was mostly over. Many KPA soldiers who had been unable to escape hid or feigned death until captured or killed. With the linkup completed, the 27th British Commonwealth Brigade relieved 187 RCT at Sukchon and passed through for the continuation of its drive to the Chongchon River. The Australians had distinguished themselves in their first major battle in the Korean War, and the battalion was later praised for its performance.

## Background

On 26 July, the Australian government announced that it would commit the under-strength and poorly equipped 3rd Battalion, Royal Australian Regiment (3 RAR) then in Japan to South Korea, following a period of preparation. Training and re-equipment began immediately, while hundreds of reinforcements were hastily recruited in Australia as part of K Force; they soon began arriving to fill out the battalion. The battalion's commanding officer, Lieutenant Colonel Floyd Walsh, was replaced by Lieutenant Colonel Charles Green. An officer with extensive operational experience fighting the Japanese in New Guinea during the Second World War, Green took over from Walsh due to the latter's perceived inexperience.

On 23 September, 3 RAR embarked for Korea, arriving at Pusan on 28 September. There it joined the British 27th Infantry Brigade, a garrison formation hurriedly committed from Hong Kong by the British as the situation deteriorated around the Pusan Perimeter in late August to bolster the US Eighth Army under the command of Lieutenant General Walton Walker. Commanded by Brigadier Basil Coad, the brigade was renamed the 27th British Commonwealth Brigade and consisted of the 1st Battalion, Argyll and Sutherland Highland Regiment (1 ASHR), the 1st Battalion, Middlesex Regiment (1 MR) and 3 RAR. The two understrength British battalions had each mustered just 600 men of all ranks, while the brigade was also short on transport and heavy equipment, and had no integral artillery or armour support, for which it would rely entirely on the Americans until the 16th Field Regiment, Royal New Zealand Artillery arrived in January 1951. As such, with a strength of nearly 1,000 men, the addition of 3 RAR gave the brigade increased tactical weight as well as expediently allowing the Australians to work within a familiar organisational environment, rather than being attached to a US formation. Also under the command of the brigade were a number of US Army units, including 155 mm howitzers from the US 90th Field Artillery Battalion, M4 Sherman tanks from the US 89th Tank Battalion and a company of US combat engineers.

## Prelude

### Opposing forces

By the time 3 RAR arrived in the theatre, the North Koreans had been broken and were in rapid retreat, with General Douglas MacArthur's UNC forces conducting a successful amphibious assault at Inchon and breakout from the Pusan Perimeter on the southern tip of the Korean Peninsula. A steady advance began, driving the North Koreans northwards towards the 38th Parallel. The 27th British Commonwealth Brigade was airlifted from Taegu to Kimpo Airfield north of Seoul on 5 October. However, its vehicles had to move by road, driving 420 kilometres (260 mi) and did not arrive until 9 October. It was attached to the US 1st Cavalry Division under the command of Major General Hobart R. Gay. The brigade would function as a separate task force at a considerable distance from, and without physical contact with, that division or other friendly units. On 16 October, the brigade took over from the US 7th Cavalry Regiment as the vanguard of the UNC advance into North Korea, its axis intended to take it through Kaesong, Kumchon and Hungsu-ri to Sariwon, then through Hwangju to Pyongyang. Although the North Koreans had suffered heavily in the preceding weeks, they continued to resist strongly, while a lack of accurate maps and the narrowness of the roads made rapid movement difficult for the advancing UNC forces. During this time, 3 RAR had a platoon of US M4 Sherman tanks attached and a battery of field guns in direct support.

The 27th British Commonwealth Brigade moved 70 kilometres (43 mi) from Kumchon, with the Argylls capturing Sariwon, an industrial town 54 kilometres (34 mi) south of Pyongyang, on 17 October. Supported by 3 RAR and US tanks, the Highlanders killed 215 KPA and took several thousand prisoners for the loss of one man killed and three wounded in a one-sided action. Prior to the attack, the Australians had moved through the town to establish a blocking position 8 kilometres (5.0 mi) to the north. During the evening, 3 RAR encountered a KPA force withdrawing north. Using the same road and moving in the same direction, the KPA mistook the Australians and Argylls for Russians in the poor light and were bluffed into surrendering, with the Australians capturing thousands of KPA and their weapons and equipment following a brief exchange. Mounted on a tank, the 3 RAR second-in-command, Major Ian Ferguson, captured over 1,600 KPA soldiers with just an interpreter. Australian involvement had been limited, however, and they regarded their first exposure to the fighting in Korea as a relatively minor incident. Pyongyang fell to US and South Korean troops on 19 October. On 21 October, the 27th British Commonwealth Brigade passed to the command of the US 24th Infantry Division under the overall command of Major General John H. Church, while the US 1st Cavalry Division remained in Pyongyang to complete its capture. Coad had hoped to rest his men at Pyongyang; however, the advance continued north with little respite and the brigade moved through the village of Samgapo. The British and Australians were ordered to seize Chongju.

The previous day, Colonel Frank S. Bowen's US 187th Airborne Regimental Combat Team (187 RCT) had parachuted into drop zones around Sukchon and Sunchon. 187 RCT was tasked with cutting off retreating KPA forces withdrawing up the west coast of the Korean Peninsula and releasing US and South Korean POWs. The 187th Airborne Infantry Regiment's 1st and 3rd Battalions (1/187 and 3/187 ABN) dropped southeast of Sukchon to seize the town, hold the high ground to the north and block the highway and rail line south of Sukchon, cutting off the main supply route and line of communication that led north from Pyongyang; the 2nd Battalion (2/187 ABN) was dropped near Sunchon, 24 kilometres (15 mi) east of Sukchon to seize the town, block another highway and rail line, and intercept a POW train that US intelligence indicated was moving northwards by night from Pyongyang. The US paratroopers were to hold their positions until relieved by the US Eighth Army push northwards to link up with them, a task that was expected to be completed within two days. After observing the airdrop, General MacArthur flew to Pyongyang where he announced to the press that the airborne operation was a brilliant tactical maneuver that seemed to have been a complete surprise to the North Koreans. Estimating that 30,000 KPA, perhaps half of those remaining in North Korea, had been caught between 187 RCT in the north and the US 1st Cavalry Division and ROK 1st Infantry Division to the south at Pyongyang, he predicted that they would soon be destroyed or captured. He termed the airdrop an “expert performance” and said, “This closes the trap on the enemy.” MacArthur's optimism would not be supported by events. Anxious not to expose the lightly armed and lightly equipped paratroopers by projecting them too far forward of the Eighth Army advance, MacArthur had kept them back too long. The operation came too late to intercept any significant KPA elements. By this time, most of the KPA remnants had already succeeded in withdrawing north, and had crossed safely behind the Chongchon River, or were in the process of doing so, while Premier Kim Il Sung's government and most important officials had moved to Kanggye in the mountains 32 kilometres (20 mi) southeast of Manpojin on the Yalu River. Through no fault of their own, the paratroopers were less successful on one other score, that of rescuing POWs who were being moved northwards from Pyongyang; most of the American POWs had been moved to more remote parts of North Korea and were unable to be rescued. Although sound in concept, the US airborne operation may have had more chance of success had a complete airborne division been employed.

Only the KPA 239th Regiment remained, having been ordered to delay the UNC forces as they attempted to follow up. With a strength of 2,500 men, the regiment occupied positions on the high ground astride the road and rail lines east of Yongyu, 12 kilometres (7.5 mi) south of the US drop zone at Sukchon.

## Battle

### KPA 239th Regiment is encircled, 21 October 1950

The most important action growing out of the 187 RCT airdrop occurred in the 3/187 ABN sector, about 13 kilometres (8.1 mi) south of Sukchon in the vicinity of Op'a-ri and Yongyu. At 02:30 on 21 October, K Company repulsed an attack on its Sukchon–Pyongyang highway roadblock by an estimated company-sized KPA force that attempted to break through to the north. At 09:00, the 3/187 ABN command post (CP) advanced two combat teams from the roadblock position in a reconnaissance-in-force to clear the Sukchon–Yongyu road towards Pyongyang and establish contact with the 27th British Commonwealth Brigade that was leading the 24th Infantry Division northwards from Pyongyang. I Company was assigned to clear the rail line and K Company was given the mission of clearing the highway. I Company reached Op'a-ri at 13:00, where it was attacked by an estimated battalion-strength KPA force equipped with heavy mortars and automatic antiaircraft guns. After a two-and-a-half-hour firefight, I Company, with two rifle platoons overrun by the KPA and 90 men missing, was forced to withdraw west of the rail line to Hill 281. Failing to exploit the advantage, the KPA withdrew to defensive positions on the high ground around Op'a-ri. Meanwhile, K Company, receiving harassing fire during its advance along the highway, proceeded to a point about 1.6 kilometres (0.99 mi) north of Yongyu, where it encountered a KPA force of about three companies. After a heavy firefight, the Americans forced the KPA to withdraw to defensive positions on the high ground to the south and east of the town. K Company continued into Yongyu, taking up defensive positions in the town and on Hill 163 to the north of the town.

I and K Companies now occupied defensive positions roughly opposite each other—at Op'a-ri (Hill 281) overlooking the rail line and at Yongyu (Hill 163) overlooking the highway—yet these positions were now almost 5 kilometres (3.1 mi) apart and unable to mutually support each other. The distance separating the highway and the railway which ran north either side of Yongyu was greater at that point than anywhere else between Sukchon and Pyongyang. Extending on a southwest–northeast axis, and cutting across both the highway and rail line at Yongyu and Op'a-ri, is a line of high hills offering the best defensible ground between Pyongyang and the Chongchon River. Here, the KPA 239th Regiment had taken up defensive positions, deploying a battalion in each locality. The last organised KPA unit to leave Pyongyang, its mission was to fight a delaying action against the expected UNC advance from Pyongyang. Now, as a result of the unexpected US airborne operation, it was encircled and found itself attacked from two separate points in its rear. The KPA 239th Regiment, by this time convinced that both routes to the north had been blocked by the US airborne forces, would attempt one last push to regain contact with the other KPA forces that had infiltrated northwards.

### British and Australians advance to Yongyu, 21–22 October 1950

In the days prior, the US I Corps had continued its movement northwards as part of the general advance of the US Eighth Army. Following the capture of Pyongyang, the corps commander, Major General Frank W. Milburn, ordered the advance to continue to the MacArthur Line, running approximately 35 kilometres (22 mi) south of the Yalu River. The US 24th Infantry Division, to which the 27th British Commonwealth Brigade was now attached, was ordered to lead this attack. On the division's right flank three ROK divisions, the ROK 1st Infantry Division, under the US I Corps, and the ROK 6th and 8th Infantry Divisions under control of the ROK II Corps, were deployed to the east and would also be committed to the attack northwards. The British and Australians had covered 122 kilometres (76 mi) in the previous two days, advancing rapidly until slowed by rain. A Company, 3 RAR, was engaged by snipers from a nearby village without suffering casualties. The Sherman tanks proceeded to heavily engage the KPA positions in the village, which was then cleared by the Australian infantry who killed five KPA and took three prisoners. As the rain ceased a KPA T-34 tank, which had remained concealed during the earlier fighting, engaged D Company, 3 RAR, and was knocked out by the US tanks. An unmanned SU-76 self-propelled gun was also located nearby and neither it nor the tank were found to have any fuel.

Now the vanguard of the Eighth Army, the British and Australians crossed the Taedong River using a sandbag bridge at Pyongyang at noon on 21 October, moving north on the main highway to Sukchon with the task of reaching the Chongchon River. Under the command of Lieutenant Colonel George Nielson, 1 ASHR pushed up the road until fired upon by KPA forces in the hills to the south of the town, with snipers engaging the column as it turned west out of the river valley around 16:00. Encountering only light resistance from a small KPA force of approximately 75 men which was then scattered by tank fire, the Argylls successfully cleared the foothills by last light on 21 October. Approaching Yongyu, Coad decided to halt for the night. The Argylls sent a patrol into the town, establishing initial contact with 3/187 ABN, marrying up with K Company which was established in a number of houses on the northern edge of Yongyu and on Hill 163 immediately above their position. A strong KPA force was believed to be nearby, with at least 300 men thought to remain in the town.

### KPA 239th Regiment breakout, 22 October 1950

At 00:15, the KPA 239th Regiment attempted a breakout to the north, launching multiple attacks against K Company, 187 ABN, at Yongyu. During the first attack, K Company's positions in the town and at its roadblock on the northern outskirts of town were assaulted by a large KPA force estimated at two battalions. Nearby, the British and Australians could hear the sounds of heavy fighting between the Americans and KPA 1.6 to 3.2 kilometres (1 to 2 mi) to the north. Half an hour later, a small KPA force attacked A Company, 1 ASHR, with grenades, killing two men and wounding two more before being repulsed, having suffered one killed and one wounded. Following two more KPA attacks, the Americans abandoned the roadblock after running out of ammunition and withdrew to 3/187 ABN's main defensive position 3.2 kilometres (2.0 mi) to the north. Detecting the withdrawal, the KPA attacked again at 04:00, leaving a small blocking force to hold the remnants of K Company in place in Yongyu, and concentrated the majority of its forces on the road to Sukchon. To the south, the British and Australians began to fear that the Americans had been overrun. A short time after the KPA 239th Regiment's main body passed through, the remaining elements withdrew from Yongyu and moved to join the main body. The KPA 239th Regiment moved north along the road, arriving at a point 910 metres (1,000 yd) south of the 3/187 ABN CP at around 05:00. The KPA stopped to reform, not realizing that 3/187 ABN's Headquarters and Headquarters Company (HHC) and L Company, 187 ABN were dug in along the road.

At 05:45, the KPA 239th Regiment started moving north again and ran blindly into 3/187 ABN's HHC and L Company's perimeter elements. They were immediately engaged with heavy losses, not only by direct fire from the HHC but also by enfilading fire from L Company. Stunned by the volume and severity of the fire, it took the KPA 239th Regiment about an hour to reorganize and deliver an attack. A group of about 300–350 KPA engaged L Company and attempted to flank and envelop its positions. Another group of about 450 KPA engaged the HHC. The KPA fire became exceedingly accurate as the firefight progressed. Hard-pressed, the 3/187 ABN CP radioed the 187 RCT CP at Sukchon describing the situation and requesting reinforcement. 187 RCT's request for armoured reinforcement was received by the 24th Infantry Division's headquarters in Pyongyang. Yet, with the US division still well to the rear, the Sherman tanks of the US 89th Tank Battalion encamped with the 27th British Commonwealth Brigade on the Pyongyang-Sukchon road just south of Yongyu was the closest formation, and they were ordered forward to assist 3/187 ABN.

By dawn, the North Koreans and Americans had fought each other to a standstill after heavy fighting overnight and the previous day; the KPA 239th Regiment was almost exhausted, yet, in danger of being destroyed, it prepared for a final attempt to break out.

### Fighting in the apple orchard, 22 October 1950

Overnight, Brigadier Coad had directed Lieutenant Colonel Green's 3 RAR to take the lead when the brigade moved out the following morning and Green decided to send Captain Archer P. Denness' C Company through Yongyu to advance as rapidly as possible to effect the relief of 3/187 ABN to the north.

At first light on 22 October, A and C Company, 1 ASHR, advanced into Yongyu to clear the town of any remaining KPA before the Australians passed through. Elsewhere, 1 MR took up defensive positions to the north of Yongyu. The Argylls moved through the town, using high-explosive and white phosphorus hand grenades to flush out the KPA, setting fire to many of the buildings. As planned, at 07:00, 3 RAR was ordered to move through Yongyu towards Sukchon to link up with 187 RCT and close the gap between the two forces. C Company, 3 RAR, passed through the burning town mounted on the Sherman tanks of D Company, US 89th Tank Battalion, and headed north on the Yongyu–Sukchon road.

At 09:00, the Australian column was stopped by small arms and light mortar fire from a hillside apple orchard about 1.5 kilometres (0.93 mi) north of Yongyu. Lieutenant Colonel Green, traveling with the 3 RAR headquarters group, proceeded forward to Captain Denness' location. C Company had driven into the rearguard of the KPA 239th Regiment as it was forming up for a final assault on 3/187 ABN. The strong KPA force of approximately 1,000 men allowed C Company, 3 RAR and the battalion's tactical headquarters group to pass before engaging them. Denness did not have a lot of information; there had been no contact with the Americans who were believed to be located nearby. The KPA-held apple orchard lay between the advancing Australians and the US paratroopers, blocking any relief attempt. Brigadier Coad's order citing the urgent need to link up with the Americans dictated Green's decision. Rather than preparing a deliberate attack and potentially allowing the KPA time to organise their defences, Green chose to force his leading company through at once in order to seize the initiative and continue the pursuit. An encounter battle developed as 3 RAR carried out an aggressive quick attack from the road, with US tanks in support.

Preparing for the assault, Lieutenant Colonel Green informed brigade headquarters of his plans and was advised that 3/187 ABN was believed to be about 1,500 metres (1,600 yd) further north; however, as the exact location of the Americans was unclear, the indirect fire available to support the attack would be limited. The US tanks were also initially under orders not to fire for fear of hitting their own men. With mortars and artillery unavailable, the Australians proceeded to attack regardless, with the tanks carrying C Company turning east towards the KPA positions in the apple orchard. At 09:30, Captain Denness dismounted 7 and 8 Platoons and aggressively counterattacked off the line of march into the apple orchard, while 9 Platoon, commanded by Lieutenant David Butler, was left near the road to protect the Australian flank. Supported by the Sherman tanks' cannons and coaxial machine guns, the Australians charged the KPA positions with bayonets, Bren guns, Owen guns, Lee–Enfields, and hand grenades. In the face of this determined attack, many of the KPA left their pits in an attempt to move to safety, only to suffer heavy casualties after exposing themselves to the fire of the two assaulting platoons, the flanking platoon and the US tanks in support. The speed and ferocity of the attack surprised the defenders, and the Australians quickly overran the KPA outposts despite the lack of indirect fire. The KPA, many of whom were recently trained conscripts, were then forced to withdraw for the loss of only four Australians wounded. For his leadership in coordinating the assault, Denness was later awarded the Military Cross, while Private Charles McMurray received the Military Medal for bravery.

More than 70 KPA were killed in the initial attack, while a further eight or nine were killed as the Australians cleared the position, setting fire to the KPA dug-outs and forcing the remaining defenders to flee. As the KPA broke, Lieutenant Colonel Green pushed A and B Company onto the higher ground to the right of C Company with the intention of clearing the ridge overlooking the highway, while D Company moved forward on the left of the road towards 9 Platoon. Meanwhile, the battalion tactical headquarters, which had followed closely behind C Company as they assaulted, came under attack in the apple orchard east of the road and was forced to fight off a group of KPA, with the regimental police and the battalion signallers fighting back-to-back to defend themselves. Withstanding the attack, the Australians eventually killed 34 KPA for the loss of three men wounded. Despite becoming personally involved in the heavy fighting, Green continued to skilfully control the battle throughout. D Company was ordered to clear the KPA threatening battalion headquarters, as well as sending a platoon forward to establish contact with the Americans. Running low on ammunition, 3/187 ABN had been in contact throughout the morning and continued to suffer casualties. However, having been forced off the high ground, the KPA were now caught between the advancing Australians and the US paratroopers to the north.

Unable to move north, the KPA attempted to escape across the open rice fields to the west, through the gap between the 27th British Commonwealth Brigade and 3/187 ABN. The KPA again suffered heavy casualties, with many cut down by tank and rifle fire from C Company, 3 RAR. Some of the survivors took refuge among a number of haystacks and rice stooks in front of 9 Platoon, from where they engaged the Australians with sniper fire. Others fled east, escaping to the higher ground where they dispersed. D Company, 3 RAR, was ordered to clear pockets of resistance remaining within the battalion position. Meanwhile, 1 MR passed through the Australians and with the tanks linked up with 3/187 ABN at 11:00. Following three hours of fighting the battle was largely over by midday; however, many of the KPA that had been unable to escape continued to refuse to surrender, hiding or feigning death until individually flushed out. After clearing their objectives 7 and 8 Platoon had moved forward towards 9 Platoon, which then clashed with a number of KPA stragglers in the paddy fields. C Company, 3 RAR, deployed in an extended line and a substantial action soon developed. In a scene Coad later likened to driving snipe, the Australians proceeded to sweep the area, kicking over stacks of straw and shooting the KPA soldiers they found hiding in them as they attempted to flee. For his leadership, Lieutenant Butler was awarded the US Silver Star, while Private John Cousins received the US Bronze Star for his role in the action.

## Aftermath

### Casualties

Despite the uncertain situation and the lack of indirect support, Lieutenant Colonel Green's tactical handling of the Australian battalion had been bold, and his decision to move quickly through Yongyu and to attack off the line of march proved decisive. Preoccupied with fighting the Americans to their north, the KPA were unprepared for the Australians to attack from the rear. Caught between the US paratroopers and the 27th British Commonwealth Brigade, the KPA 239th Regiment was practically destroyed. KPA casualties in the apple orchard were 150 killed, 239 wounded and 200 captured, while Australian casualties numbered just seven men wounded. Including those engaged by the Argylls, total KPA losses during the fighting with the 27th British Commonwealth Brigade exceeded 200 killed and 500 captured. The survivors fled westwards. In their first major battle in Korea, the Australians had distinguished themselves, and the battalion was later praised for its performance. The action became known as the "Battle of the Apple Orchard", while the Royal Australian Regiment was later granted the battle honour "Yongju". Boosting their confidence, the success prepared the Australians for the battles which they were to face in the months that followed. Meanwhile, 3/187 ABN reported killing 805 KPA and capturing 681 in the fighting around Yongyu. Altogether, US casualties during the Sukchon-Sunchon operation were 48 killed in action and 80 wounded and a further one killed and 56 injured in the jump.

The Middlesex Battalion was ordered to push on to Sukchon, and after successfully relieving the Americans in place by nightfall, the battalion occupied a defensive position 1.6 kilometres (0.99 mi) north. The 27th British Commonwealth Brigade and US 24th Infantry Division continued their advance up the highway. Intending to defeat the KPA and bring the war to a close, the UNC forces pushed towards the Yalu River, on the Chinese border. However, resistance continued to be met as the 27th British Commonwealth Brigade crossed the Chongchon River, and they now moved towards Pakchon. On 24 October, General MacArthur had removed all restrictions on the movement of his forces south of the Yalu River and prepared for the final phase of the UNC advance, defying a directive of the US Joint Chiefs of Staff and risking Chinese intervention on behalf of North Korea. An intense period of fighting followed and the Australians were involved in a number of major battles over the coming days.

### Subsequent operations

On the afternoon of 25 October, a platoon from 3 RAR was fired on by two companies of KPA as they crossed the Taeryong River to conduct a reconnaissance of the west bank, and although they were forced to withdraw, the Australians took 10 prisoners with them. Acting as the forward elements of the brigade, that evening Lieutenant Colonel Green sent two companies across the river to establish defensive positions and they broke up a frontal assault on their positions with mortars while the KPA were in the process of forming up. Sixty KPA supported by a T-34 tank then attacked the forward Australian companies at Kujin early the following morning, resulting in Australian losses of eight killed and 22 wounded. However, the KPA suffered heavy casualties including over 100 killed and 350 captured, and the Australians succeeded in defending the bridgehead after the KPA withdrew. Intelligence indicated that the British and Australians were facing the KPA 17th Tank Brigade, which was preparing a last line of defence at Chongju, 70 kilometres (43 mi) away. With the war considered all but over, the 27th British Commonwealth Brigade continued to pursue the KPA towards Chongju; however, the advance increasingly encountered strong resistance as they approached the Manchurian border.

1950 battle of the Korean War

Battles and operations of the Korean War in 1950

Battles of the Korean War involving Australia

Battles of the Korean War involving North Korea

Battles of the Korean War involving the United Kingdom

Battles of the Korean War involving the United States


Guillermo Mota

Guillermo Reynoso Mota (born July 25, 1973) is a Dominican former professional baseball relief pitcher in Major League Baseball. In his career, he pitched for the Montreal Expos, Los Angeles Dodgers, Florida Marlins, Cleveland Indians, New York Mets, Milwaukee Brewers and San Francisco Giants. Mota is 6 feet 6 inches (1.98 m) tall and weighs 240 pounds (110 kg). He throws and bats right-handed. He throws three pitches: a fastball, a slider and a circle changeup.

Mota was originally signed by the New York Mets in 1990 as an infielder. After several years in their organization, he was drafted by the Montreal Expos in the Rule 5 draft in 1996 and converted into a pitcher in 1997. Mota had a 2.96 ERA in 1999, his rookie season, but he struggled in his next two seasons and was traded to the Los Angeles Dodgers prior to 2002. His struggles continued in his first year with the Dodgers, but Mota had a career year in 2003, as he had a 6–3 record with a 1.97 ERA in 76 games. He became the setup man to closer Éric Gagné in 2004, but was traded to the Florida Marlins midseason. Mota started 2005 as their closer, but Todd Jones took over the role when Mota got hurt in April. Following the year, Mota was traded to the Boston Red Sox.

Before Mota ever played for the Red Sox, however, he was traded again to the Cleveland Indians. He struggled in his time with the Indians in 2006 and was designated for assignment by them in August. The New York Mets acquired him, and Mota improved mightily upon joining them. Following the season, he became a free agent, but he again signed with the Mets. After struggling in 2007, he was traded to the Milwaukee Brewers. He got off to a poor start with Milwaukee in 2008 but improved in the second half. Following the season, Mota became a free agent and signed with the Dodgers again. He had his best year since 2004 and became a free agent again after the season. For the first time in his career, in 2010 he signed a minor league contract with the San Francisco Giants. After making the team out of spring training, Mota won his first career World Series despite struggling at times during the season. Following the season, he signed another minor league contract with the Giants and made the team out of spring training again. During the 2012 season, Mota became one of three players in league history to fail a drug test twice when it was shown he tested positive for Clenbuterol, a performance-enhancing drug.

## Early life

Mota was born on July 25, 1973, in San Pedro de Macorís, in the Dominican Republic. As a youth, he attended Jose Joaquin Perez High School. After high school, he was signed by the New York Mets on September 7, 1990, by scout Eddy Toledo.

## Professional career

### Minor leagues

After two years playing baseball in the Dominican Republic, Mota was assigned to the rookie-league Gulf Coast League Mets in 1993 as a third baseman. He had a batting average of .249 with one home run and one stolen base and amassed a .934 fielding percentage in 43 games. The next season, he spent most of the year with the rookie-league Kingsport Mets of the Appalachian League, although he went hitless in four at bats in one game with the St. Lucie Mets of the single-A advanced Florida State League. With Kingsport, he batted .245 while he struck out 78 times in 245 at-bats.

In 1995, Mota was moved to the shortstop position and assigned to the single-A Capital City Bombers of the South Atlantic League. With the Bombers, he batted .243 and struck out 127 times in 400 at-bats while committing 40 errors at shortstop. In 1996, he returned to the St. Lucie Mets, where he batted .234 with 90 strikeouts in 304 at-bats while committing 21 errors. Following the season, he was selected by the Montreal Expos in the Rule 5 draft.

The Expos converted Mota to a pitcher in 1997 and assigned him to the Cape Fear Crocs of the South Atlantic League. Starting 23 of his 25 games for the Crocs, he had a 5–10 record with a 4.36 earned run average (ERA) and 112 strikeouts in 126 innings.

In 1998, the Expos moved Mota to the bullpen, and he began the season with the single-A advanced Jupiter Hammerheads of the Florida State League. He posted a 3–2 record with a 0.66 ERA and two saves in 20 games and was promoted to the Harrisburg Senators of the double-A Eastern League during the season. With the Senators, he had a 2–0 record with a 1.06 ERA and four saves in 12 games.

Mota began the 1999 season with the Ottawa Lynx of the triple-A International League. With the Lynx, he had a 2–0 record with a 1.89 ERA and five saves in 14 games.

### Montreal Expos (1999–2001)

#### 1999

Mota was called up to the Expos on May 2 to replace relief pitcher Shayne Bennett, who had been demoted to Ottawa after struggling in his first four games. Mota made his major league debut the same day, pitching a scoreless inning in an 8–7 loss to the St. Louis Cardinals. He got his first major league decision on May 11, when, after pitching 2+2⁄3 scoreless innings, he gave up a walk-off home run in the tenth inning to Luis Gonzalez in a 4–3 loss to the Arizona Diamondbacks. On June 1, he won his first major league game, also against Arizona after pitching three scoreless innings in the Expos' 10–8 victory on June 1. On June 9, he hit a three-run home run in his first major league at bat (against Mark Guthrie) in a 13–1 victory over the Boston Red Sox. On August 29, he allowed one run in one inning and was the winning pitcher in an 8–6 victory over the Cincinnati Reds. The win (the Expos' eighteenth in August) set a new Expos' record for wins in a month. Mota had a 1.49 ERA over his first 32 games of the year, but a 15.00 ERA over his next six games brought his ERA for the season to 3.40. However, he collected a 1.38 ERA over his final 12 games to bring his ERA for the season down to 2.93, and he finished the year with a 2–4 record in 51 games.

#### 2000

The Expos sent Mota to Ottawa to begin the 2000 season. However, he was called up to the Expos on May 20, and in his first game of the season with them, he gave up one run in one inning in an 8–7 victory over the Houston Astros. On June 11, he was the losing pitcher when he pitched 1⁄3 inning and gave up two runs in an 8–3 loss to the Toronto Blue Jays. He was returned to Ottawa on June 17 after posting a 12.60 ERA in his first 12 games with the Expos. Mota was recalled at the end of the month, but after appearing in one game (on July 1), he was returned to the Lynx. However, he was recalled on July 19 after Tony Armas Jr. was placed on the disabled list. Mota was returned to the minor leagues on July 27 when Hideki Irabu returned from the disabled list, but he was recalled soon after. However, Mota appeared in only one game before he was again returned to the minors, and he did not return to the Expos again until the beginning of September. At this point, he had a 9.98 ERA through 17 games. On September 11, in the second game of a doubleheader against the Philadelphia Phillies, he got his only win of the year by pitching one-third of an inning in a 7–6 victory. He had a 1.84 ERA over his final 12 games to finish the year with a 1–1 record and a 6.00 ERA in 29 games. With Ottawa, he had a 4–5 record with a 2.29 ERA and seven saves in 35 games.

#### 2001

In 2001, Mota made the Expos out of spring training for the first time in his career. On May 12, he had a 1.59 ERA through his first 20 games of the year. However, eight earned runs allowed over his next six games raised his ERA to 4.00. Afterwards, though, he had a 2.08 ERA through his next 12 games. On June 17, he was the winning pitcher when he threw a scoreless inning in a 4–1 victory over Toronto. In his next game, on June 19, he was the losing pitcher when he gave up three runs (only one run was earned) without recording an out in a 4–1 loss to the New York Mets. However, after that 12-game stretch, he gave up five earned runs over his next four games to bring his ERA up to 4.29. On July 13, he was placed on the disabled list for the first time in his career with right shoulder tendinitis. Mota returned at the beginning of September, but he had a 10.57 ERA and two losses in his final 11 games of the year. He finished the season with a 1–3 record and a 5.26 ERA in 53 games.

### Los Angeles Dodgers (2002–2004)

#### 2002

Mota began spring training with the Expos in 2002, but was traded to the Los Angeles Dodgers with outfielder Wilkin Ruan for pitcher Matt Herges and infielder Jorge Nunez on March 23. He failed to make the Dodgers' major league club in spring training and was assigned to the Las Vegas 51s of the triple-A Pacific Coast League to begin the season. He was called up on April 20 when Kevin Brown was placed on the disabled list. After appearing in two games, he was returned to Las Vegas on April 30 when Brown came off the disabled list. On May 17, he was called up a second time. In 22 games through July 14, he had a 2.43 ERA. On June 3, he pitched a scoreless inning and earned the win in an 11–5 victory over the Colorado Rockies. However, he was returned to Las Vegas on July 28 after he had a loss and a 13.50 ERA over his next seven games. He did not return to the Dodgers until August 26, when Kevin Beirne was demoted to the minors. That same day, he was the losing pitcher when he gave up three runs (two earned) in his third inning of work in a 12-inning 6–3 loss to Arizona. He was the losing pitcher again on September 13 when he gave up three runs in the seventh inning and blew a 4–2 lead over Colorado. He posted a 3.92 ERA over his final 14 games of the year to finish with a 1–3 record and a 4.15 ERA in 43 games. With the 51s, he had a 1–3 record with a 2.95 ERA in 20 games.

#### Conflict with Mike Piazza

On March 28, 2002, Mota hit Mike Piazza, catcher for the Mets at the time, with a pitch in a spring training game against the Mets. After Mota was removed from the game, Piazza grabbed him by the neck and had to be separated from Mota by other players. Piazza received a \$3,000 fine for his actions. Next season, in a spring training game against the Mets on March 12, Mota hit Piazza with a pitch. Piazza charged the mound, starting a brawl, and both players were ejected from the game. After the game, Piazza entered the Dodgers' clubhouse looking for Mota. Informed that Mota had left, Piazza searched the clubhouse before leaving. Mota said that hitting Piazza was not intentional, but both he and Piazza were suspended five games in the regular season and fined—Mota \$1,500 and Piazza \$3,000. Mota's suspension was later reduced to four games.

#### 2003

In 2003, Mota earned a roster spot with the Dodgers after spring training. From May 1 to 27, he pitched 15+2⁄3 consecutive scoreless innings. On May 23, against the Milwaukee Brewers, he got his first save when he pitched three scoreless innings in a 6–4 victory. Manager Jim Tracy used him to get the save because he wanted to rest closer Éric Gagné. On May 29, Mota struck out six batters in three innings in a 12–5 loss to Colorado. From June 11 through July 17, he threw 19+2⁄3 consecutive scoreless innings. On July 13, he hit his second career home run (against Joe Roa) in a 9–3 victory over Colorado. In August, he had a 2–0 record with a 0.44 ERA in 21 games. Mota finished the season with a 6–3 record and a 1.97 ERA in 76 games, and his 105 innings pitched were the most by a Dodger reliever since 1985, when Tom Niedenfuer threw 106+1⁄3. His 105 innings pitched led National League (NL) relief pitchers and were just two shy of American League leader Steve Sparks. Mota, Gagné, Tom Martin, and Paul Quantrill were the first relief pitcher teammates to appear in at least 76 games in a season. His opponent batting average of .205 ranked tenth among NL relievers, and left-handers' .181 average against him ranked fourth in the NL.

#### 2004

After Quantrill became a free agent, Mota became the setup man for Gagné in 2004. He started the season with eight straight scoreless games. From June 27 to July 16, he did not allow a run in 10 straight games. On July 29, he started a career-high five-game winning streak when he got a win by pitching two scoreless innings in a 2–1 victory over the San Francisco Giants. He was the winning pitcher when he pitched two scoreless innings in an 8–5 victory over the Anaheim Angels on July 3 in a game notable for Gagné getting the final save of his 84 straight converted save chances. On July 30, a day before the trade deadline, Mota had a 2.14 ERA in 52 games. That day, he was traded to the Florida Marlins with Juan Encarnación and Paul Lo Duca for Hee-seop Choi, Brad Penny, and Bill Murphy.

### Florida Marlins (2004–2005)

Upon joining the Marlins, Mota was named the closer because Armando Benítez, the Marlins' closer, was injured. On August 5, he entered a game in the eighth inning with the Marlins leading 7–5 and got his first save as a Marlin in an 11–5 victory over Arizona. However, that was his only save opportunity before he was returned to the setup role because of the return of Benítez from the disabled list. Mota had a 4.81 ERA in 26 games with the Marlins, although it would have been only 3.06 if he had not given up seven runs in his final two games of the year. He finished the season with a 9–8 record and a 3.07 ERA in 78 games. His nine wins were tied with Ryan Madson for second in the NL by a relief pitcher, and his 96+2⁄3 innings pitched led NL relievers. His opponent batting average of .196 was fifth-best among NL relievers.

In 2005, Mota was named the Marlins' closer in spring training since Benítez became a free agent following the 2004 season. He did not get a save opportunity until April 22, which he converted in a 4–2 win over Cincinnati. He got his second save of the year the next day in another 4–2 win over Cincinnati. However, he was placed on the disabled list on May 1 (retroactive to April 24) with inflammation in his right elbow. He was activated on May 27, but Todd Jones, who had been filling in for Mota, remained the closer. Mota had a 1.69 ERA through his first 11 games, but 12 earned runs allowed over his next seven games raised his ERA to 7.27. On June 24, he was the winning pitcher in the Marlins' 7–4 victory over the Tampa Bay Devil Rays. He got his only other win of the year on August 30, when he gave up a run in two innings in a 7–6 victory over St. Louis. Mota posted a 3.81 ERA over his final 38 games to finish the season 2–2 with a 4.70 ERA in 56 games. On November 24, Mota was traded with Josh Beckett and Mike Lowell to the Boston Red Sox for four prospects: Jesús Delgado, Harvey García, Hanley Ramírez, and Aníbal Sánchez.

### Cleveland Indians (2006)

Mota never played a game with the Red Sox, as of January 27, 2006, he was traded to the Cleveland Indians with Andy Marte, Kelly Shoppach, a player to be named later (eventually Randy Newsom), and cash considerations for Coco Crisp, David Riske, and Josh Bard. The trade was postponed slightly because Mota failed to pass a physical, so the Indians put him on a conditioning program before spring training. However, he was still expected to be the setup man for closer Bob Wickman. He started the season well, as he did not allow an earned run in his first seven games. However, he struggled after that, and he lost the setup role to Rafael Betancourt in May. Over his next 27 games, Mota had a 7.89 ERA, and opponents batted .314 against him. On August 11, he was designated for assignment after he had a 1–3 record with a 6.21 ERA in 34 games. On August 20, he was traded to the New York Mets with cash for a player to be named later. To date, his time with the Indians was his only stint in the American League.

### New York Mets (2006–2007)

On September 1, Mota was the winning pitcher when he pitched a scoreless inning in an 8–7 victory over Houston. He got another win by pitching a scoreless inning on September 12 in a 6–4 victory over Florida. With the Mets, he had a 3–0 record with a 1.00 ERA and 19 strikeouts in 18 games to finish the season 4–3 with a 4.53 ERA in 52 games. He made the playoffs for the first time in his career as the Mets won the NL East. In the first game of the 2006 National League Division Series against the Dodgers, Mota was the winning pitcher when he pitched two innings, although he blew a 4–1 lead by giving up three runs and allowing the Dodgers to tie the game. Mota pitched two scoreless innings in the Mets' series-winning 9–5 victory over the Dodgers in Game 3. In the 2006 National League Championship Series, Mota appeared in five of the seven games in the series. He blew a lead in an eventual Game 2 loss, but he did not give up a run in the other four games as the Mets lost to St. Louis in seven games. On October 30, he filed for free agency.

On November 1, 2006, Mota became the fifteenth MLB player to be suspended for using performance-enhancing drugs (and the first to be suspended for fifty games) when he was suspended for the first fifty games of 2007. However, the Mets re-signed him to a two-year, \$5 million contract on December 7. After spending two weeks in the minors, Mota rejoined the Mets on May 30, 2007. He struggled in his first 16 games, collecting a 7.71 ERA in them. In his next 15 games, however, he amassed a 1.89 ERA. During those games, on August 3, he was the winning pitcher when he threw a scoreless inning in a 6–2 victory over the Chicago Cubs. He struggled after that, though, as he had a 7.48 ERA over his final 21 games of the season. On August 28, he was the losing pitcher when he gave up a walk-off home run to Ryan Howard in the 10th inning of a 4–2 loss to Philadelphia. He earned the win on September 12 in a 4–3 victory over the Atlanta Braves despite losing a two-run lead in the eighth inning. His final decision of the season came on September 16, when he gave up three runs without recording an out in a 10–6 loss to Philadelphia. Mota finished the season with a 2–2 record and a 5.76 ERA in 52 games. On November 20, he was traded to the Milwaukee Brewers for Johnny Estrada.

### Milwaukee Brewers (2008)

Mota started the 2008 season with a 2.20 ERA in his first 15 games. On May 11, Brewers manager Ned Yost removed Gagné from the closer's role and decided to use different pitchers in save opportunities. The next day, Mota got his first save since 2005 in an 8–3 victory over St. Louis. However, that was his only save of the season, and Salomón Torres took over the closer's role. Mota began to struggle after the save, as he had a 9.00 ERA over his next 19 games to bring his ERA to 5.77 at the All-Star break. However, he began pitching better after the All-Star break as he posted a 1.59 ERA in his final 24 games of the season. On August 24, Mota was the winning pitcher in a 4–3 victory over Pittsburgh when he entered the game with the bases loaded and no outs and did not allow a run to score in one inning of work. He finished the season with a 5–6 record and a 4.11 ERA in 58 games, and he returned to the playoffs as the Brewers made the playoffs for the first time in 26 years. In the first game of the 2008 National League Division Series, he pitched a scoreless 1⁄3 inning in a 3–1 loss to Philadelphia. His only other appearance of the playoffs that year came in Game 4 (the final game of the series) when he allowed a solo home run to Pat Burrell in the final 1+1⁄3 innings of a 6–2 loss. On November 3, Mota filed for free agency.

### Second stint with the Dodgers (2009)

On January 13, 2009, Mota returned to the Dodgers upon signing a one-year contract. His second stint with the Dodgers got off to a bad start, as he posted a 9.00 ERA in his first 15 games of the season. However, his statistics improved when he compiled a 0.26 ERA over his next 29 games to lower his season ERA to 2.92. From June 24 through July 29, Mota gave up no runs in 17 games (20+1⁄3 consecutive innings pitched). However, he had a 4.97 ERA over his next 13 games. On August 4, in a 17–4 victory over Milwaukee, Mota was ejected after he hit Brewers first baseman Prince Fielder with a pitch (in retaliation for Chris Smith hitting Manny Ramirez a few innings earlier, according to Dodgers catcher Russell Martin). After the game, Fielder attempted to gain entry into the Dodgers' clubhouse to confront Mota but was stopped by teammates. Both Mota and Fielder were fined by Major League Baseball for their actions. On August 31, Mota was placed on the disabled list with an ingrown toenail to make room for Ronnie Belliard on the roster. He was reactivated on September 14. However, after posting a 5.40 ERA in his final four games of the year, he was left off the Dodgers' playoff roster. He finished the season with a 3–4 record and a 3.44 ERA (his lowest since 2004) in 61 games. On November 6, he filed for free agency.

### San Francisco Giants (2010–2012)

On February 2, 2010, Mota signed a minor league contract with the San Francisco Giants with an invitation to spring training, marking the first time he was a non-roster invitee. On April 4, he was placed in the final spot in the Giants' bullpen. He started his tenure with the Giants with nine consecutive scoreless outings. On May 5, he got his only save of 2010 in a 9–6 victory over Florida. Mota took over the setup role in May, but lost it after allowing five runs and losing one of three games from June 10 to 13. He compiled a 1.27 ERA over his first 23 games, but a 7.48 ERA over his next 28 games raised his ERA to 4.78. On July 4, he intentionally walked four batters in 1+1⁄3 innings (due to runners reaching third base with nobody out in the 14th and 15th innings) and was the losing pitcher when he allowed a run in the 15th inning of a 4–3 loss to Colorado. On August 23, he was placed on the disabled list with iliotibial band syndrome to make room for Cody Ross on the Giants' roster. He returned to the Giants on September 6. Mota did not give up an earned run in his final five appearances of the season to finish the year with a 1–3 record and a 4.33 ERA in 56 games, and he made the Giants' playoff roster as they won the NL West. However, he was not used until Game 2 of the 2010 World Series, when he pitched a scoreless ninth inning in a 9–0 victory over the Texas Rangers. His only other postseason appearance came when he pitched 1+1⁄3 scoreless innings in a 4–2 loss in Game 3. However, Mota won his first World Series when the Giants defeated Texas 4 games to 1 in the series. After the series, he filed for free agency.

On December 19, Mota signed another minor league contract with an invitation to spring training with the Giants. He won one of the final two spots in the Giants' bullpen on March 30, 2011. On April 16, after Giants' starter Barry Zito was injured in the second inning, Mota pitched a career-high 4+1⁄3 innings, giving up one run and earning the win in a 5–3 victory over Arizona.

On May 7, 2012, MLB announced that they were suspending Mota for 100 games due to his testing positive for Clenbuterol, a performance-enhancing substance. This was his second suspension as he had previously been suspended for 50 games in 2006.

### Kansas City Royals

Mota signed a minor league deal with the Kansas City Royals on January 16, 2014. However, he announced his retirement on March 2, 2014.

## Pitching style

Mota had three different kinds of pitches: a fastball, a slider, and a circle changeup, and occasionally he mixed in a splitter and a curveball. Because of a record of wildness with his fastball, his slider became his out pitch.

## See also

- List of doping cases in sport
- List of players with a home run in first major league at bat

Dominican baseball pitcher (born 1973)

Baseball players from San Pedro de Macorís

Dominican Republic expatriate baseball players in Canada

Dominican Republic expatriate baseball players in the United States

Dominican Republic sportspeople in doping cases

Major League Baseball players from the Dominican Republic


Helicoverpa zea

Helicoverpa zea, commonly known as the corn earworm, is a species (formerly in the genus Heliothis) in the family Noctuidae. The larva of the moth Helicoverpa zea is a major agricultural pest. Since it is polyphagous (feeds on many different plants) during the larval stage, the species has been given many different common names, including the cotton bollworm and the tomato fruitworm. It also consumes a wide variety of other crops.

The species is widely distributed across the Americas with the exception of northern Canada and Alaska. It has become resistant to many pesticides, but can be controlled with integrated pest management techniques including deep ploughing, trap crops, chemical control using mineral oil, and biological controls.

The species migrates seasonally, at night, and can be carried downwind up to 400 km. Pupae can make use of diapause to wait out adverse environmental conditions, especially at high latitudes and in drought.

## Distribution

The corn earworm is found in temperate and tropical regions of North America, with the exception of northern Canada and Alaska as it cannot overwinter in these areas. Helicoverpa zea found in the eastern United States also does not overwinter successfully. They live in Kansas, Ohio, Virginia, and southern New Jersey, but survival rate is mainly affected by the severity of the winter. Corn earworm moths regularly migrate from southern regions to northern regions depending on winter conditions. They are also found in Hawaii, the Caribbean islands, and most of South America, including Peru, Argentina, and Brazil.

Cotton earworms have also been reported from China in 2002.

The taxonomy of Helicoverpa was poorly understood for a long time. Many older works referring to "Heliothis obsoleta", a synonym of H. armigera, are actually about H. zea.

## Lifecycle and description

### Eggs

Eggs are individually deposited on leaf hairs and corn silks (not in reference given). The eggs are initially pale green in color, but over time they turn yellowish and then grey. Eggs are 0.5 mm in height and average about 0.55 mm in diameter. They hatch after 66 to 72 hours of development. Once larvae have breached the chorion, they spend up to 83% of eclosion making an exit hole larger than their heads. Larvae spend the rest of the time making a silk meshwork around the exit hole; this both helps them escape the shell and helps them find the shell afterwards so they can feed on it. After feeding on their shell, larvae rest about 3 minutes before they begin feeding on the plant material around them.

### Larvae

Following hatching, larvae feed on the reproductive structures of the plant and usually develop through four to six instars. Initially, the young larva feed together, and this stage is their most destructive stage. Through maturation, older larvae become aggressive and cannibalistic, leaving one or two larvae per feeding site (See Interfamilial Predation). They usually have orange heads, black thorax plates, and a body color that is primarily black. Their bodies can also be brown, pink, green, and yellow with many thorny microspines. Mature larvae migrate to the soil, where they pupate for 12 to 16 days.

### Pupae

Larvae pupate 5 to 10 cm below the soil surface. Pupae are brown in color; they measure 5.5 mm wide and 17 to 22 mm long. The biggest environmental factor that affects the pupal developmental rate is temperature, primarily soil temperature. This is because proper insulation facilitates development, and soil temperatures below 0 degrees Celsius correlate to higher pupal mortality. Another factor that influences pupal development is soil moisture. Pupal mortality is high in wet soil, where the moisture level is between 18 and 25 percent. Dehydration can also lead to high death rates among pupae, if soil moisture is as low as 1 to 2 percent.

### Adults

Adults have forewings that are yellowish brown in color and have a dark spot located in the center of their body. The moths have a wingspan ranging from 32 to 45mm, and live over thirty days in optimal conditions. However, the life span ranges from five to fifteen days on average. They are nocturnal and hide in vegetation during the day. Adult moths collect nectar or other plant exudates from a large number of plants, and live for 12 to 16 days. Females can lay up to 2,500 eggs in their lifetime.

## Economic impact

### Damage

The corn earworm is a major agricultural pest, with a large host range encompassing corn and many other crop plants. H. zea is the second-most important economic pest species in North America, next to the codling moth. The estimated annual cost of the damage is more than US\$100 million, though expenditure on insecticide application has reached up to \$250 million. The moth's high fecundity, ability to lay between 500 and 3,000 eggs, polyphagous larval feeding habits, high mobility during migration, and a facultative pupal diapause have led to the success of this pest.

### Control

Two kinds of control measures have been advocated since the 19th century. One aims at total pest population reduction, while the other is aimed at protection of the particular crop. As of 2013, integrated pest management (IPM), an array of techniques and approaches to control pests, was recommended. Practices such as deep ploughing, mechanical destruction, and trap crops are also used to kill different instars. Chemical control is widely successful, and includes the use of applying mineral oil inside the tip of each corn ear, which suffocates the young larvae. Pesticides are one method by which corn earworm populations are controlled; however, since they have been widely used, the insects have become resistant to many pesticides. The use of biological controls, such as the bacterium Bacillus thuringiensis and various forms of nematodes, is also common, although not without their own problems. Corn earworm moths are not always vulnerable to the bacterium, and they are only afflicted by nematodes once the larvae have pupated and dropped to the ground. Strains of maize have been genetically modified to produce the same toxin as the bacterium, and are referred to as Bt-corn.

## Survival

### Natural enemies

More than 100 insect species prey on H. zea, usually feeding on eggs and larvae. The insidious flower bug (Orius insidiosus), a pirate bug, feeds on the eggs of H. zea, thus acting as a biological control agent. Some plants emit a blend of chemicals in response to damage from H. zea, which attract parasitic insects. Cardiochiles nigriceps, a solitary endoparasitoid wasp, makes use of these volatile plant compounds to identify the presence of H. zea. When the wasps find damaged host plants, they hover around and then search for the host with their antennae. When the females find their prey, they use their antennae to position themselves and deposit eggs into the host. The braconid wasp Microplitis croceipes, which deposits its eggs inside a living caterpillar, is also an important parasitoid of both H. zea and the related species Heliothis virescens. When larval densities are high, a fungal pathogen, Nomuraea rileyi, can cause an outbreak of disease. However, pupal mortality is high not because of predators, but because of harsh weather conditions, collapsing pupal chambers, and disease.

### Larval predation

As the larvae mature, they become increasingly aggressive. Although they have host plants surrounding them, H. zea larvae attack and eat other insects. When presented with a second-instar larva of Urbanus proteus, the corn earworm larva grasps the insect, rolls onto its side to form a semicircle, and begins feeding on the insect's posterior end. If the U. proteus begins to bite out of defense, H. zea rotates the larva 180° and uses its mandibles to puncture the head capsule, killing the insect. Then, the H. zea larva rotates the U. proteus back to its original position and continues feeding until the insect is entirely consumed. Even when presented with up to five U. proteus larvae, H. zea engages in the unique behavior, as the larvae have a higher affinity for lepidopterous prey over plant material. H. zea raised in a low-moisture environment has a lower pupal weight and a longer developmental time than those raised in environments of high moisture, so a nutritional benefit exists to such aggressive feeding behavior under such conditions.

## Movement

### Migration

Helicoverpa zea is a seasonal, nocturnal migrant, and adults disperse, weather permitting, when there are poor reproductive conditions. In short-range dispersal, the moths move within the crop and low over the foliage. This type of dispersal is mostly independent of wind currents. Long-range dispersal involves adults flying up to 10 meters above the ground and moving downwind from crop to crop. Migratory flights occur up to 1–2 km above the ground and can last for hours. Migration of 400 km is common for such flights as moths are carried downwind. Helicoverpa zea caterpillars are usually intercepted on produce transported by air-freight transportation. Most activity is restricted to the night-time. Some moths display vertical take-off flight, which carries them above the flight boundary layer and allows them to undertake migratory movement in upper wind systems. During mating, males engage in high-speed directed flight in search of pheromone plumes (See Pheromone Production).

### Diapause

Pupae have the ability to enter facultative diapause, the state of arrested development and growth in response to a change in the environment. By preparing themselves for a major change in environmental conditions, they can increase reproductive success. Diapause increases with increasing latitude. In tropical conditions, populations breed continuously, and only 2-4% of pupae diapause. In subtropical and temperate regions, most individuals diapause. Individuals who don't enter diapause in these areas emerge in late fall and die without reproducing. Drought-responsive diapause has also been observed in the summer.

## Feeding

### Host plants

Helicoverpa zea has a wide host range, attacking vegetables that include corn, tomato, artichoke, asparagus, cabbage, cantaloupe, collards, cowpea, cucumber, eggplant, lettuce, lima bean, melon, okra, pea, pepper, potato, pumpkin, snap bean, spinach, squash, sweet potato, and watermelon. However, not all of these are good hosts. While corn and lettuce are shown to be great hosts, tomatoes are less beneficial, and broccoli and cantaloupe are poor hosts. Corn and sorghum are most favored by corn earworms. Various signs reveal the presence of these moths. Young maize crops have holes in their leaves, following whorl-feeding on the apical leaf. Eggs can be found on silks on larger plants, and silks display grazing evidence. The soft, milky grains in the top few centimeters of corn cobs are eaten as the corn ears develop. One larva per cob can be observed. Bore holes are observed in cabbage and lettuce hearts, flower heads, cotton bolls, and tomato fruits. Sorghum heads are grazed, and legume pod seeds are eaten.

### Corn

Helicoverpa zea earns its nickname the corn earworm for its widely known destruction of cornfields. The corn earworm feeds on every part of corn, including the kernels. Severe feeding at the tip of kernels allows entry for diseases and mold growth. Larvae begin feeding on the kernels once they have reached third instar. Larvae penetrate 9 to 15 cm into the ear, with deeper penetration occurring as the kernels harden. Larvae do not eat the hard kernels, but take bites out of many kernels, lowering the quality of the corn for processing.

### Soybeans

Helicoverpa zea is the most common and destructive pest of soybean growth in Virginia. About one-third of Virginia acreage is treated annually with insecticide, costing farmers around 2 million dollars. The degree of damage varies on the size of the pest infestation, the timing, and the stage of the plant. However, soybean plants are capable of withstanding a large amount of damage without substantial yield loss depending on soil moisture, planting date, and weather. If the damage is early in the plants life, then damage will mostly be to the leaves. Plants compensate for the damage by processes such as increasing seed size in remaining pods. Most damage happens in August, when the plants are flowering. Attacks that happen after August do much less damage because many pods have developed tougher walls that H. zea can't penetrate. Infestations that affect pod formation and seed filling have the potential to reduce yields, and because this happens in the later stages of plants, they have less time to compensate.

Female moths are attracted to flowering soybean fields. The most severe infestations occur between flowering and when pods become fully developed. Large-scale outbreak is associated with time of peak flowering, when most pods are developed, and peak moth flight, for giant. Moths are also attracted to drought stressed soybeans or fields with poor growth. Dry weather leads to quick drying of corn plants, compelling moths to leave and seek other hosts. Heavy rainfall also decreases corn earworm populations because it drowns pupae in their soil chambers, limits moth flight, washes eggs from leaves, and creates favorable conditions for fungal diseases that kill caterpillars.

## Mating

### Pheromone production

A hormone produced in the brain of the female moths controls sex pheromones. The hormone is released into the hemolymph to stimulate pheromone production. Pheromone biosynthesis-activating neuropeptide (PBAN) is a peptide that regulates pheromone production in moths. It acts on the pheromone gland cells using calcium and cyclic AMP. Although the photoperiod regulates the release of PBAN to some extent, the chemical signals from the host plant supersede the effect from the time of day. Female Helicoverpa zea in corn fields do not produce pheromones during the night until they encounter corn. Several natural corn silk volatiles like the plant hormone Ethylene as a plant hormone#ethylene induce H. zea pheromone production. The presence of the silk from an ear of corn is enough to cause pheromone production, and physical contact between females and corn is unnecessary. This evolutionary mechanism enables the moths to coordinate their reproductive behavior with the availability of food. Female moths often become depleted of sex pheromone after mating within 2 hours of separation from the male. The pheromonostatic peptide (PSP), a protein 57 amino acids long found in the male accessory gland, is what causes depletion of the female's sex pheromone. This capability in males has been selected for because it increases the reproductive fitness of those that carry it, since other males will not be attracted to a female without a sex pheromone; thus, the female will bear only the first male's offspring. The transfer of a spermatophore without accessory gland products does not stop female pheromone production, but does stop the female's calling behavior. Intense selection acting on males to manipulate female reproductive physiology promotes rapid evolution of specific molecules, and male-derived pheromone suppressing factors exhibit positive selection. When females are infected with the virus Helicoverpa zea nudivirus 2, they produce 5 to 7 times the amount of sex pheromone than uninfected females.

### Mortality

Sperm competition and chemicals introduced to females through mating have a negative effect on females and their lifespan. In males, production of the spermatophore, sperm, and secondary chemicals reduces their lifespan. As the number of copulations increase, the rate of mortality also increases in both sexes.

### Flight behavior

Males must first wait to sense a female's pheromones before they can locate her. Before males engage in flight to find a female, they warm-up by shivering the major flight muscles to reach thoracic temperature optimal to sustain flight, around 26 degrees Celsius. The thermoregulatory shivering activities of males were measured as they were exposed to different sex-related olfactory cues. Males are found to heat up more quickly in the presence of a female pheromone and take-off at a lower thoracic temperature than males who are exposed to other chemical scents. Since heating up to the right temperature leads to better flight performance than flying immediately, there is a trade-off between sub-optimal flight performance and rapid onset of directed flight. Helicoverpa zea males exposed to an attractive pheromone blend thus spend less time shivering and increase their heating rate. Thermoregulatory behavior of unrestrained moths is associated with competition for access to females, showing the ecological trade-off.

## Gallery

Species of moth