In this study, two strains of the mitochondrial lineage Q1 of Bemisia tabaci MED species, characterized by a different complement of facultative bacterial endosymbionts, were tested for their susceptibility to be attacked by the parasitoid wasp Eretmocerus mundus, a widespread natural enemy of B. tabaci. Notably, the BtHC strain infected with Hamiltonella and Cardinium was more resistant to parasitization than the BtHR strain infected with Hamiltonella and Rickettsia. The resistant phenotype consisted of fewer nymphs successfully parasitized (containing the parasitoid mature larva or pupa) and in a lower percentage of adult wasps emerging from parasitized nymphs. Interestingly, the resistance traits were not evident when E. mundus parasitism was compared between BtHC and BtHR using parasitoids originating from a colony maintained on BtHC. However, when we moved the parasitoid colony on BtHR and tested E. mundus after it was reared on BtHR for four and seven generations, we saw then that BtHC was less susceptible to parasitization than BtHR. On the other hand, we did not detect any difference in the parasitization of the BtHR strain between the three generations of E. mundus tested. Our findings showed that host strain is a factor affecting the ability of E. mundus to parasitize B. tabaci and lay the basis for further studies aimed at disentangling the role of the facultative endosymbiont Cardinium and of the genetic background in the resistance of B. tabaci MED to parasitoid attack. Furthermore, they highlight that counteradaptations to the variation of B. tabaci defence mechanisms may be rapidly selected in E. mundus to maximize the parasitoid fitness.

The successful mass-rearing of potential biological control agents is a prerequisite for sustainable pest control. In this study, the performance of 3 Trichogramma euproctidis (Girault) (Hymenoptera: Trichogrammatidae) populations collected from different locations in Khuzestan (Southwest Iran) were evaluated to optimize the egg parasitoid mass-rearing for augmentative biological control of lepidopteran pests. We aimed to investigate the effects of both population origin and host quality on biological traits of ovipositing females (number of parasitized eggs) and of their progeny (development time, survival rate, sex ratio, longevity, and fecundity). The effect of host quality was assessed by allowing the parasitoid to oviposit into 1, 2, 3, or 4-day-old Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs. The 3 T. euproctidis populations developed successfully regardless the age of the host eggs. However, we found significant variation among populations and a strong influence of host quality on the traits investigated. Progeny performance in all populations decreased with increasing host age. The best-performing population (collected in Mollasani) showed the highest parasitization rate, highest survival rate, and progeny sex ratio with the greatest percentage of females. A life table corroborated these findings with superior estimates of the net reproductive rate (R₀), intrinsic rate of increase (r), and reduced generation time (T) for the Mollasani population on 1-day-old host eggs. We conclude that ample variation exists among T. euproctidis populations and that rearing the Mollasani population on young rather than old eggs of E. kuehniella would be recommended to implement the biological control programs to target lepidopteran pests in Southwestern Iran.

This paper is a contribution to the characterisation by an integrated approach of the species Microterys chalcostomus (Dalman), a parasitoid of mealybugs and apparently a predator of kermesid eggs. Until now, the species, whose type is in good condition, could be identified only by the meagre original description by Dalman and subsequent notes by Graham. Nonetheless, it appears to be extremely common in Europe, hence the need for a thorough morphological and molecular characterisation. Systematic notes on closely related species of Microterys parasitoids of mealybugs are included.

Platynota stultana is a Nearctic moth of economic importance for many crops in North America. It is a quarantine pest in Europe, where Mediterranean regions, with warm climates similar to those of the moth’s native range, are at risk of invasion. To date, the species is established only in Spain. It has been reported sporadically in Italy, but it is unknown whether these were transient findings or the result of an establishment. In this study, the presence of P. stultana in the Campania region, Southern Italy, was recorded. Adults of both sexes were found in different locations and in two consecutive years, suggesting that the species is established. Sequencing the COI gene identified three haplotypes of P. stultana, suggesting possible multiple introductions. The two most numerous haplotypes were identical to haplotypes from Florida. Phylogenetic analysis showed that the P. stultana clade splits into two subclades. The Italian haplotypes are all grouped into the same subclade. Our data suggest that P. stultana is expanding its range of invasion into Southern Italy, where, due to global warming, it may find increasingly favorable conditions and become an economic pest. A monitoring plan is required to allow timely implementation of control measures.