308 Invasive Stink Bugs and Related Species (Pentatomoidea)
Aphelinids typically are parasitoids of whiteflies and armored scale insects (Schmidt and Polaszek
2007), but two species have been reported from Megacopta cribraria. Rajmon and Narendran (2001)
reported that Ablerus sp. emerged from 60% of eggs sampled in India. However, they indicated that spe-
cies of Ablerus are reported to be hyperparasitoids, so they may not be direct parasitoids of M. cribraria.
Encarsiella boswelli has been reported from eggs of M. cribraria in India (Polaszek and Hyat 1990) but
appears to be uncommon and has not been reported from Asia (Ruberson et al. 2013).
5.4.3.1.2 Parasitoids in the New World
Ruberson et al. (2013) reported that eggs of Megacopta cribraria were not attacked by native para-
sitoids in the United States but did indicate that a single tachinid fly, Phasia robertsonii ( Tow n s e n d),
emerged from an adult bug in Georgia. Golec et al. (2013) also reported parasitism of adults by
a tachinid fly, Strongygaster triangulifera (Loew). Parasitism rates for the latter species were
5.14% overall, but females appeared to be preferred (9.34% of females and 0.93% of males were
parasitized).
Eggs of Megacopta cribraria collected in Georgia, Alabama, and Mississippi in 2013, and Florida
in 2014, were parasitized by Paratelenomus saccharalis (Gardner et al. 2013b, Medal et al. 2015). This
parasitoid was not previously known from the New World and appears to be a separate unintentional
introduction. Although the species was being evaluated in quarantine, it had not been approved for
release and the genetics of the quarantined individuals and those appearing suddenly in the southeast-
ern United States apparently are different (Wayne A. Gardner, personal communication). How this
parasitoid was introduced and how it dispersed over a large geographic area before first being found are
unknown. A subsequent study in organic soybeans in Georgia (Tillman et al 2016) found that oviposi-
tion and percent parasitism tended to be higher in conventional tillage soybean (58.4 %) than in no-till
soybean (44.9 %). Late in the season parasitism was 82-95 %. These data suggest that this parasitoid
has become a significant factor in reducing the number of M. cribraria in Georgia and perhaps the rest
of the southeastern United States.
Other than Paratelenomus saccharalis, other egg parasitoids have not been reported in the US with one
exception. In North Carolina and Virginia, Dhammi et al. (2016) recovered Gonatocerus sp. (Mymaridae),
Eretmocerus sp. (Aphelinidae), Encarsia sp. (Aphelinidae), and Ooencyrtus sp. (Encyrtidae) from eggs
of Megacopta cribraria but did not indicate levels of parasitism. Medal et al. (2016b) found that eggs of
M. cribraria were not parasitized by Trissolcus japonicus (Ashmead) (Scelionidae), a potential biologi-
cal control agent for Halyomorpha halys Stål (Pentatomidae), in the laboratory.
5.4.3.2 Parasitic Nematodes
There are no reports of parasitic nematodes in Megacopta cribraria in the Old World, but Stubbins et
al. (2015) reported that a mermithid nematode was found parasitizing adults of M. cribraria in soybeans
in South Carolina. The nematode was found in a single field (out of five sampled) and about 4.7% of
females (only females were dissected) were found to be parasitized. Males and females also were held
for nematode emergence and nematodes emerged from 7 (14%) of the males and 5 (10%) of the females.
Most emerged from the caudal end of the bug, but one emerged from near the head. In a subsequent
study (Stubbins et al. 2016b), M. cribraria again was found to be infected by this nematode with as many
as 15% of females and 9% of males infected. Nematodes were reported from nymphs for the first time
and as many as 20% of fifth instar nymphs were found to be infected. The nematode was identified as
Agamermis sp.
5.4.3.3 Predators
There are relatively few reports identifying predators of Megacopta cribraria in the Old World. Ahmad
and Moizuddin (1976) reported Reduvius sp. (as Reduviius sp.) (Reduviidae) preying on this bug, and
Borah and Sarma (2009a) recorded a spider, Oxyopes shweta Tikader (Oxyopidae), and a bug, Antilochus
coquebertii (F.) (Pyrrhocoridae), as predators of nymphs and adults of M. cribraria. Finally, Poorani et al.