Modification of Fitness in Species and Strains of Flour Beetles due to X‐Ray and DDT

Abstract

Insecticides and ionizing radiations can induce population changes which under selection are beneficial or harmful. Such changes are known in some cases to have a genetic basis. Studies were designed to determine the early effects of DDT and x-radiation, singly and in combination, on mortality and productivity of flour beetle species and strains ( Tribolium confusum Duval "Chicago standard" and T. castaneum Herbst "Brazil cl" and "Sooty"). Five replicate populations each containing ten pairs of virgin beetles x-rayed with 0, I, 2 or 4 kR of x-rays (250 kvp, 30 rna, 0.25 mm Cu + 1.0 mm AI filtration, 0.86 mm Cu HVL and 2.5 inches between target and subjects produced I kR/min) were cultured under standard conditions in food containing 0, 5, IO, 20 or 50 ppm DDT. Every two weeks for six weeks parental mortality was recorded and living adults were placed on fresh comparable food. The old food was reincubated and F 1 adult biomass and numbers were the measures of productivity.Parental mortality was I) unaffected by x-rays, 2) increased for "Brazil cl" at 50 ppm DDT, and 3) greater for females than males but unrelated to radiation or insecticide.Productivity measurements decreased with increasing x-ray or DDT. Productivity of T. confusum was, in general, more radiation-sensitive than that of T. castaneum strains, whereas, both T. castaneum strains were more DDT -sensitive than was T. confusum. Radiation of 4 kR was almost sterilizing to T. confusum; of T. castaneum strain "Brazil cl" left no F 1 at 50 ppm DDT.Proportions of Iethals due to x-ray or DDT were considered genetic dominants and used to quantify the relationship between radiation and insecticide in combination. Observed lethality simulated that expected for genetic dominant lethal effects when "Chicago standard" and "Brazil cl" were stressed with x-ray plus DDT. In "sooty," observed lethality was consistently lower than that predicted on the assumption of dominant lethal effects; i.e., productivity was less adversely affected when both stresses were applied than that expected by multiplying the effects of singly stressed populations.Within a species "sooty" populations showed more lethality due to x-rays than did "Brazil cl" populations; DDT had the opposite effect.

Historical pesticide applications coincided with an altered diet of aerially foraging insectivorous chimney swifts

“…Increased DDT use, beginning in the late 1940s (figure 2d), may have dramatically depressed beetle prey in the diet of swifts (figure 2b), as beetle populations are particularly subject to negative long-term population impacts from DDT [29][30][31]. This negative relationship is supported by beetle populations that inversely track DDE concentrations; the proportion of beetles in the guano rebounded in the decades after DDTuse started to decline, and they declined slightly in the most recent decades coincident with a marginal increase in DDE concentrations.…”

Alguns usos e efeitos das radiações gama em >i<Zabrotes subfasciatus>/i< (Boh., 1833) (Coleoptera, Bruchidae)

“…Irradiação com raios Xi SOKOLOFF (209); E.liRTLETT, BELL (14) JAFRI (120), (121), (122) e (123); BELL (25h ERDN.AN (75), (7 8 ) (79), ( 8 0) , ( 8 1) , ( 8 3) , ( 84) , (8 6) , ( 87 ) , ( 89) , ( 90 ) , (9 1 ), ( 9 5), (9 6 ), (98L, ( 99 ) e (101), Irradiação por neutrons acelerados (f.no) ERDMAN ( 88), (89), (91), (92), (94), (96) e (97); Irradiação por raios gamas CRoO; Irradiação por raios betag TABOADA (214), BAKER (6), BAKER, TABOADA, WW1T (7) 9 (8), ( 9) e (10); NICHOLAS, WIANT (168); Irradia ção por raios"Xg AMER (1); AMER, SLATER, (2); BECIC (19), (20) e (21) 7…”

“…BECK, RA.YES (22); DOWELL (69); DUCCOFF, BOSM.A (70), ( 71), ( 72) e (73), DUCOFF, WALJ3URG (74), BAKER (6); TABOADA (214); RA.RTLETT (13); FARKAS (102), JAFRI ( 120), ( 121), ( 122) e (123); ERDW.l.AJ:.T (75), ( 78), ( 79),( 80), (81), (82), ( 83), ( 85), ( 86), ( 87), ( 89), ( 90), ( 99), ( 100) e (101); SLATER, TOBIAS, BECK, LYM.AN, MARTIN, LUCE (207); SLATER, RESCIGNO, MOO{ TOBIAS (206), MC DONALD ( 150) e (151) 7 SOKOLOFF (209) e (210); Irradi� Q ção por raios gama& HASSET, JENKINS (107) 9 SHCJ:IBGOLEVA (201); BROWNELL, NEHEMIAS 9 BUll!ER (39), VEREECKE, PELEREN'TS (225), (226) e (227); WOOD (238); SHIROISI, IIAYAKAWA, WATANABE, FUKUMACIIl, SAIWRA (203); SHIPP (202) "' ; WATTERS, MC QUEEN (232); DENNIS (65h B.ANRAM (11); BANHAM, CROOK (12); CRENSHAW (61); RLSULOV, ANASTASIEV (196); CORK (53) 9 JEFFERIES, BJl..lTIIAM (128); Tilfl'ON, :SROWER (216); PESSON (176) E�ta média foi obtida de 8 amostragens compostas de 4 amO §.…”