Bagrada hilaris (Burmeister) 227
found in the Transvaal, but the fact that it is abundant some seasons in the Cape Colony, and not in oth-
ers, seems to point to the work of some parasite in the Colony, and we at present are negotiating with
other entomologists for the importation of such parasites whenever possible.” It is not known if such a
project was initiated. Later, Gunn (1918) reported that in the Pretoria area, “... a Hymenopterous parasite
belonging to the family Chalcididae began to emerge [from the soil] in large numbers.”
All other references to parasitoids have come from observations in India and Pakistan. Four species
of parasitic Diptera have been reported from Bagrada hilaris including Sarcophaga kempi Senior-White
(Sarcophagidae) (Thompson 1950) and the tachinid flies Alophora indica (Mesnil) (as Parallophorella
indica) (Herting and Simmonds 1971, Cheema et al. 1973, Crosskey 1976), Alophora sp. (Rakshpal
1949, Cheema et al. 1973, Crosskey 1976, Azim and Shafee 1986), and Phasia sp. (Tachinidae) (Herting
and Simmonds 1971). Little is known about the effectiveness of these parasitoids. Cheema et al. (1973)
reported that only four A. (as Hyalomya) pusilla emerged from 554 adults from the western hills of
Pakistan. In India, Rakshpal (1954) reported that only male Alophora sp. emerged from male B. hilaris
and only female parasitoids emerged from female hosts. This relationship has not been reported for any
other tachinid attacking a stink bug host. A. pusilla is known from a wide range of hosts across multiple
heteropteran families. Sarcophagids are not specific to any pentatomid species or even confined to a
particular insect family. All pentatomids are probably attacked by one or more tachinids (Phasiinae).
Some are fairly specific but few have a significant impact on their hosts. Exceptions are species in the
New World genus Trichopoda that have been successfully established in Hawaii and Australia for bio-
logical control of the southern green stink bug, Nezara viridula (L.) (Davis and Krauss 1963, Coombs
and Sands 2000).
The nymphal stages of Pentatomidae are not commonly attacked. The two most common gen-
era reported from nymphal stages are the wasps Hexacladia (Encyrtidae) and Aridelus (Braconidae).
However, none has been reported from B. hilaris. Many tachinids attack the later nymphal instars of
stink bugs but normally only emerge after the host reaches the adult stage.
Pentatomid eggs are the most susceptible stage attacked by parasitoids, and several species are
known to attack Bagrada hilaris in Pakistan and India. Outside of the South African report of abun-
dant “Chalcididae” emerging from B. hilaris eggs (Gunn 1918), no specific parasitoids have been
reported from the rest of the insect’s broad distribution, but certainly must occur everywhere that
this pentatomid is endemic. Several genera and species of wasps in the family Platygastridae have
been reported from the eggs: Gryon sp. (Herting and Simmonds 1971), G. karnalensis Chacko and
Katiyar (Cheema et al. 1973), Telenomus samueli (Mani) (Mani 1941, Samuel 1942, Rajmohana
2006), Typhodytes sp. (Samuel 1942, Herting and Simmonds 1971), Trissolcus sp. (Ghosal 2006),
and Trissolcus hyalinipennis Rajmohana and Narendran (Subba Rao and Chacko 1961, Herting and
Simmonds 1971, Fergusson 1983, Rajmohana and Narendran 2007). Psix sp. nr. striaticeps (Dodd),
reared from another pentatomid, successfully attacked B. hilaris eggs in the laboratory (Cheema
et al. 1973) but has not been recovered from field collections. A detailed survey of egg parasitism
of B. hilaris (as B. cruciferarum) on maize (Narayanan et al. 1959) concluded that G. karnalensis
(as Hadrophanurus sp.) “... increases to such an extent that it exterminates the host and ultimately
proves fatal to the parasite itself.” Although egg parasitoids normally are the most important special-
ist natural enemy of stink bugs, none has been reported as this effective on any crop. Unfortunately,
the illustrations clearly show that the eggs were deposited together in regular rows, as with most
other stink bugs, and the eggs appear more elongate than the globular B. hilaris eggs, bringing into
question the identity of the host species studied. The authors do refer to Pruthi’s (1946) reference to
B. hilaris depositing eggs in the soil, and opines that perhaps in the rainy season, the bugs may prefer
to oviposit on leaves instead. Parasitoid specimens from this study were not found in museums in
India (Keloth Rajmohana, personal communication).
Samuel (1942) reported two species of parasitoids emerging from B. hilaris (as B. picta) around New
Delhi, Telenomus samueli (as Liophanurus sp.) and Typhodytes sp., and made some ecological observa-
tions on each. T. samueli parasitized 15–25% of the eggs during the season and 30% of exposed eggs in
the laboratory; only 20% were parasitized when in the soil. Freshly deposited eggs were less preferred.
Typhodytes appeared later in the season, the adults emerging with host nymphs from the soil at a rate
of 18–20% parasitism. It should be noted that Typhodytes may not be a valid taxon (Walker A. Jones,