LARVAL X‐RAY IRRADIATION INFLUENCES PROTEIN EXPRESSION IN PUPAE OF THE ORIENTAL FRUIT FLY, BACTROCERA DORSALIS

Abstract

The sterile insect technique (SIT) was developed to eradicate the new world screwworm from the southern United States and Mexico, and became a component of many area-wide integrated pest management programs, particularly useful in managing tephritid fruit flies. SIT is based on the idea of rearing and sterilizing male pests, originally by ionizing radiation, and then releasing into field, where they compete for and mate with wild females. Mating with sterile males leads to reduced fecundity to lower pest populations. There are concerns with the use and distribution of radioisotopes for SIT programs, which have led to developing X-ray irradiation protocols to sterilize insects. We considered the possibility that X-ray irradiation exerts sublethal impacts aside form sterilizing insects. Such effects may not be directly observable, which led us to the hypothesis that X-ray irradiation in one life stage creates alterations in biological fitness and protein expression in the subsequent stage. We tested our hypothesis by irradiating larvae of Bactrocera dorsalis. There are two major points. One, exposing larvae to X-ray treatments led to reduced adult emergence, fecundity, fertility, and flight capacity from the corresponding pupae and emerged adults. Two, the X-ray treatments led to substantial expression changes in 27 pupal proteins. We assorted the 67 spots representing these proteins into three groups, metabolism, development, and structure. Our interpretation is these X-ray induced changes in biological performance and protein expression indicate their adult counterparts may be disabled in their abilities to successfully compete for and mate wild females in native habitats.

Increasing radiation doses in Anastrepha obliqua (Diptera: Tephritidae) larvae improve parasitoid mass-rearing attributes

“…Radiation may induce physiological changes involving reduced phenoloxidase action in tephritid larvae. This was reported in larvae of Anastrepha suspensa (Loew) (Nation et al ., 1995), C. capitata (Mansour and Franz, 1996), and Bactrocera dorsalis (Hendel) (Chang et al ., 2016). Nevertheless, the qualitative determination of melanization is not feasible in all Anastrepha species, because observations in A. ludens larvae did not provide evidence of melanin in both D. crawfordi and U. anastrephae eggs and larvae as a signal of the host's immunological reaction (Cancino et al ., 2020).…”

Anastrepha ludens (Loew) (Diptera: Tephritidae) larvae irradiated at higher doses improve the rearing of two species of native parasitoids

“…In fact, it was shown that old larvae of Anastrepha suspensa (Loew) produce large amounts of ecdysone hormone, which negatively affects the normal development of the parasitoid within the host (Lawrence, 1991). Experiments where development times of A. ludens pupae coming from irradiated larvae and from non‐irradiated ones were compared showed that the first larvae require more time to reach the pupal stage (Chang, Goodman, Ringbauer, Geib, & Stanley, 2016; Nation, Smittle, Milne, & Dykstra, 1995). This occurrence may well be an indicator of a certain handicap in producing ecdysone hormone.…”

Irradiation of early immature Anastrepha ludens stages for the rearing of Doryctobracon areolatus (Hymenoptera: Braconidae), a fruit fly parasitoid

“…Doses of 30, 40, and 50 Gy, applied to eggs and to first and second instar larvae, were effective in suppressing the emergence of adult flies, and the delay in host pupation observed at 72 h was only significant when radiation was applied to eggs. This effect was also reported on third instar larvae of B. dorsalis (Balock et al ., 1963; Chang et al ., 2016), with no negative repercussions for the development of parasitoids (Yulo-Nazarea and Marroto, 1993; Cancino et al ., 2009 b ). Irradiation affects the pupal development of the host, but is independent of the physiology of the parasitoid (Nation et al ., 1995).…”