# The Current State and Future Potential of Microbial Control of Scarab Pests
## 4 Bacteria
### Paenibacillus popilliae/Paenibacillus lentimorbus (Milky Spore Disease)  
Bacterial control of white grubs has a long history, as the first microbial pesticide registered in North America in 1948 was _P. popilliae_, otherwise known as milky spore disease, used to combat Japanese beetle [35,36]. This bacterium was first detected in New Jersey in 1933, and it became available commercially for use on turfgrass in 1948. Milky spore disease was used in a large-scale insect control program against Japanese beetle in the 1940s [7,37]. Isolates found in infected grubs from the field showed that milky spore disease resulted from a combination of two _Paenibacillus_ species, _P. popilliae_ and _P. lentimorbus_[19,37,38]. These species are known to infect several scarab species, including \begin{table}
\begin{tabular}{l l l} \hline \(Bt\) **Toxin** & **Subspecies/Strain** & **Insect Targets** \\ \hline Cry3 Aa & \(Bt\) tenebrionis & _A. corpulenta, A. solsititale, M. melolonttha_ \\ Cry3 Ba & \(Bt\) tolworthi & _Cycloccephalus_ spp., _P. japonica_ \\ Cry7 Ab & \(Bt\) kumanotoensis & _A. corpulenta_, _P. japonica_ \\ Cry8 Aa & \(Bt\) kumanotoensis & _Ctitis_ spp., _H. oblita, H. parallela_ \\ Cry8 Ba & \(Bt\) kumanotoensis & _Ctitis_ spp., _C. boralis, C. pasadane, P. japonica_ \\ Cry8 Ca & \(Bt\) japonensis & _A. corpulenta, A. cuprea, A. exolette, Ctitis_ spp., _Cyloccephalus_ spp., _H. parallela_ \\ Cry8 Da & \(Bt\) gallariae & _A. cuprea, A. orientalis, P. japonica_ \\ Cry8 Db & \(Bt\) BBT2-5 & _P. japonica_ \\ Cry8 Fa & \(Bt\) BT185 & _A. corpulenta, H. parallela, P. japonica_ \\ Cry8 Fa & \(Bt\) BT185 & _A. corpulenta, H. oblita, P. japonica_ \\ Cry8 Ga & \(Bt\) HBF-18 & _H. oblita, H. parallela_ \\ Cry8 Na & \(Bt\) Q52-7 & _A. corpulenta, H. oblita, H. parallela_ \\ Cry8 Sa & \(Bt\) 62 & _H. serata_ \\ Cry9 Da & \(Bt\) japonensis & _A. cuprea_ \\ Cry18 Aa1 & \(Bt\) laterosporus & _M. melolonttha_ \\ Cry23 Aa/37 Aa & \(Bt\) (unknown) & _P. japonica_ \\ Cry43 Ba & \(P.\) _Ientimorbus_ & _A. cuprea_ \\ Cry43 Aa & \(P.\) _Ientimorbus_ & _A. cuprea_ \\ Cyt2 Ca & \(Bt\) SK-1007 & _P. japonica_ \\ Vip1 Ac & \(Bt\) kurtaki & _H. oblita_ \\ Vip1 Ad & \(Bt\) HBF-18 & _H. parallela_ \\ Vip2 Ae & \(Bt\) BREF24, _B. cereus_ HL12 & _H. oblita_ \\ Vip2 Ag & \(Bt\) HBF-18 & _A. corpulenta, H. oblita, H. parallela_ \\ Vip1 Ac+Vip2 Ae & \(Bt\) _coreus_ HL12 & _H. oblita_ \\ Vip1 Ad+Vip2 Ag & \(Bt\) HBF-18 & _A. corpulenta, H. oblita, H. parallela_ \\ \hline \end{tabular}
\end{table} 
Table 2: \(Bt\) toxins (n = 25) with demonstrated toxicity and negative effects on scarab species and the subspecies or strains they are derived from. Japanese beetle, masked chafer, and oriental beetle in the U.S. [39]. Spores exist in the soil and when ingested act very similarly to \(Bt\), germinating in the midgut and eventually penetrating the gut epithelium. As the bacteria multiply in the hemocoel they give the abdomen a milky white appearance and disrupt larval development. Grubs eventually die from either starvation or septicemia but mortality may not occur for several months under field conditions [19; 40]. A large-scale campaign to inoculate new areas with milky spore disease ran from 1939-1953 and was declared successful in suppressing of Japanese beetle populations [40; 41; 42]; however, subsequent issues with the large-scale production of milky spore disease have limited its effectiveness as a commercial product. The initial inoculum for the Japanese beetle control campaign were generated in vivo by grinding up infected beetles. Commercial outfits eventually claimed to develop a more cost-effective in vitro method, but issues with contamination quickly became apparent. [PERSON] and [PERSON] [43] found that the commercial product Grub Attack was comprised, not containing P. popillae, but rather _Bacillus polymxa_ and _B. amylolytica_, which do not produce milky spore disease. Subsequent attempts to correct this issue relied on additions of in vivo-produced _P.