scholarly journals Lethal and Sub-Lethal Effects of Insecticides on the Pink Hibiscus Mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae)

Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 31 ◽  
Author(s):  
Fatemeh Ganjisaffar ◽  
Sharon Andreason ◽  
Thomas Perring
Keyword(s):  
The Other ◽  
High Survival ◽  
Life Stages ◽  
Egg Hatch ◽  
Hatch Rate ◽  
Maconellicoccus Hirsutus ◽  
Adult Females ◽  
Pink Hibiscus Mealybug ◽  
Water Treatments ◽  
Control Water

The pink hibiscus mealybug, Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) is a pest of many plants, and a new problem on dates in California. The effects of seven insecticides and water on different life stages of this mealybug were studied to identify the best material for control. Water did not have any significant effect on mealybugs, but the insecticide treatments significantly affected all life stages tested. The egg hatch rate ranged from 28.5% to 17.2% for spirotetramat, bifenthrin, flupyradifurone, fenpropathrin, and buprofezin treatments, and was lower for sulfoxaflor (2.8%) and acetamiprid (0.1%). Despite high survival of neonate crawlers in the non-treated control and water treatments, 53.1% and 34.6% survived in the spirotetramat and buprofezin treatments, respectively; survival was zero in the other treatments. Spirotetramat and buprofezin caused very low mortality of nymphs in the first day post-treatment, but mortality significantly increased over time and reached 42.8% and 50.6% by day 6, respectively. The other treatments were highly toxic to the nymphs (79.4–99.4% on day 6). Insecticides also had a significant effect on the feeding ability of nymphs. By day 6 after treatment, 73.9% to 100% of nymphs treated with different insecticides stopped feeding although they were still alive. Insecticides showed no effect on the mortality of adult females, but the percentages of ovipositing females were significantly reduced (51.1% to 10.6%) in all insecticide treatments, except buprofezin, which was not statistically different from water and the non-treated control. In the process of our studies, we identified abnormalities in the appearance of eggs from females treated with various insecticides, and these aberrant eggs are described.

The effect of exposure to conspecifics on restlessness in the parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae)

2007 ◽  
Vol 139 (5) ◽  
pp. 678-684 ◽  
Author(s):  
B.H. King
Keyword(s):  
Habitat Quality ◽  
Parasitoid Wasp ◽  
Poor Quality ◽  
The Other ◽  
Dispersal Ability ◽  
Nasonia Vitripennis ◽  
Adult Females ◽  
Selection For ◽  
The Difference ◽  
Abundance And Distribution

AbstractWhen habitat quality is variable, there should be strong selection for the ability to detect and respond to the variation. Adult females of the parasitoid wasp Nasonia vitripennis (Walker) are known to increase their restlessness (the proportion of time in locomotion) both during and after exposure to a poor quality host. Doing so provides a mechanism for leaving a poor host and potentially finding a better host. This study examined whether restlessness also changes in response to competition as indicated by the presence of adult conspecifics. Both restlessness and the probability of dispersing across an inhospitable environment were greater when a female was with another female than when she was alone. However, restlessness did not remain elevated after the other female was removed. In contrast with females, restlessness of males did not increase either during or after exposure to other males, and the probability of dispersing across an inhospitable environment was unaffected by the presence of another male. The difference between females and males may be related to differences in dispersal ability and in the abundance and distribution of hosts versus mates.

A new male-killing parasitism:Spiroplasmabacteria infect the ladybird beetleAnisosticta novemdecimpunctata(Coleoptera: Coccinellidae)

Parasitology ◽  
2006 ◽  
Vol 132 (6) ◽  
pp. 757-765 ◽  
Author(s):  
M. C. TINSLEY ◽  
M. E. N. MAJERUS
Keyword(s):  
Phylogenetic Analysis ◽  
Sex Ratio ◽  
High Efficiency ◽  
Sex Ratios ◽  
Egg Hatch ◽  
Hatch Rate ◽  
Male Killing ◽  
Offspring Sex ◽  
Novel Host ◽  
Males And Females

Whilst most animals invest equally in males and females when they reproduce, a variety of vertically transmitted parasites has evolved the ability to distort the offspring sex ratios of their hosts. One such group of parasites are male-killing bacteria. Here we report the discovery of females of the ladybirdAnisosticta novemdecimpunctatathat produced highly female-biased offspring sex ratios associated with a 50% reduction in egg hatch rate. This trait was maternally transmitted with high efficiency, was antibiotic sensitive and was infectious following experimental haemolymph injection. We identified the cause as a male-killingSpiroplasmabacterium and phylogenetic analysis of rDNA revealed that it belongs to theSpiroplasma ixodetisclade in which other sex ratio distorters lie. We tested the potential for interspecific horizontal transfer by injection from an infectedA. novemdecimpunctataline into uninfected individuals of the two-spot ladybirdAdalia bipunctata. In this novel host, the bacterium was able to establish infection, transmit vertically and kill male embryos.

scholarly journals Reproductive diapause in Nysius huttoni White (Heteroptera Lygaeidae)

2002 ◽  
Vol 55 ◽  
pp. 308-311
Author(s):  
X.Z. He ◽  
Q. Wang ◽  
A. Carpenter
Keyword(s):  
Life Cycle ◽  
Immature Stages ◽  
Life Stages ◽  
Reproductive Diapause ◽  
Entire Life ◽  
Entire Life Cycle ◽  
Adult Females ◽  
Critical Photoperiod

The induction of reproductive diapause of Nysius huttoni was studied in the laboratory at 20 1C and 60 10 RH under a series of photoperiod regimes 168 h 1410 h 1212 h and 1014 h lightdark Reproductive diapause was considered to have occurred if females failed to lay eggs for 50 days after emergence The sensitivity of different life stages to diapauseinducing photoperiods varied When newly emerged females whose immature stages had been reared at 168 h were transferred to 1014 h and 1212 h 467 and 793 of them entered reproductive diapause respectively However when fifth instar nymphs were transferred from 168 h to 1014 h and 1212 h 100 of adult females entered reproductive diapause If the entire life cycle was maintained at 1014 h and 1212 h 667 and 400 of females entered reproductive diapause respectively The critical photoperiod for reproductive diapause was estimated to lie between 1311 h and 135105 h

scholarly journals The Impact of Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) on Control of Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudococcidae)

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 131 ◽  
Author(s):  
Zhenqiang Qin ◽  
Jianhui Wu ◽  
Baoli Qiu ◽  
Shaukat Ali ◽  
Andrew G. S. Cuthbertson
Keyword(s):  
Prey Consumption ◽  
The Other ◽  
Life Stages ◽  
Functional Responses ◽  
Cryptolaemus Montrouzieri ◽  
Important Predator ◽  
Major Pest ◽  
Dysmicoccus Neobrevipes ◽  
The Impact ◽  
Agave Sisalana

Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) is an important predator of the mealybug Dysmicoccus neobrevipes (Hemiptera: Pseudococcidae), a major pest of Agave sisalana in China. Limited reports on the efficacy of C. montrouzieri against D. neobrevipes are available. This study reports the predatory efficacy and functional response of C. montrouzieri against D. neobrevipes under laboratory conditions. The prey consumption rate per day of 4th instar larvae of C. montrouzieri feeding on 1st instar D. neobrevipes nymphs (241.3 mealybugs) was the highest among the different larval life stages of the beetle. For C. montrouzieri, the prey consumption per day of adult females (19.8 mealybugs) was significantly higher compared to males (15.2 mealybugs) when feeding on 3rd instar D. neobrevipes nymphs. The functional responses of C. montrouzieri on 1st and 2nd instar D. neobrevipes nymphs were determined as Holling type II. The search rates of C. montrouzieri 4th instar larvae towards the 1st and 2nd instar nymphs of D. neobrevipes were higher than those of the other beetle life stages. In addition, the handling times of 4th instar larvae were shorter than those of the other beetle life stages. The results from this study indicate that C. montrouzieri can be used as a predator of D. neobrevipes and, therefore, it should be evaluated further for use as a biocontrol agent in D. neobrevipes management programs.

The Toxic Effects of Fatty Acids and Their Salts on the Balsam Woolly Aphid, Adelgespiceae (Ratz.)

1975 ◽  
Vol 5 (4) ◽  
pp. 515-522 ◽  
Author(s):  
George S. Puritch
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Saturated Fatty Acid ◽  
Capric Acid ◽  
The Other ◽  
Toxic Effects ◽  
Life Stages ◽  
Woolly Aphid ◽  
Oleic And Linoleic Acids

Fatty acids and their potassium soaps were screened for their toxicity to different life stages and eggs of the balsam woolly aphid (Adelgespiceae (Ratz.)). The most effective fatty acids for causing aphid mortality were in two major groups, one centering around capric acid (C10) within the low-chain saturated fatty acid series and the other around oleic acid (C18:1), within the unsaturated 18-carbon fatty acids. The potassium soaps were better aphicides than the corresponding acids; the soaps of caprylic, capric, oleic, and linoleic acids were the most effective. Eggs were less sensitive to the soaps than later stages of the aphid, and there was a large variation in their response to the soap treatments. The possibility of using fatty acids and soaps as a control for the balsam woolly aphid is discussed.

Influence of soil water content on the supply of phosphate to plants

Soil Research ◽  
1986 ◽  
Vol 24 (3) ◽  
pp. 435 ◽  
Author(s):  
MCH Mouat ◽  
P Nes
Keyword(s):  
Water Treatment ◽  
P Uptake ◽  
The Other ◽  
Water Volume ◽  
Phosphate Adsorption ◽  
Lolium Perenne L ◽  
Water Treatments ◽  
Water Holding ◽  
P Supply ◽  
High Phosphate

Ryegrass (Lolium perenne L.) was grown in a pot trial in soil of high phosphate adsorption capacity at 10 levels of P-supply and at two water regimes, one regularly adjusted to the water-holding capacity of the pots corresponding to a water potential of -2 to -3 kPa, and the other at 20% less water volume corresponding to - 20 kPa. P uptake was lower in the lower water treatment at all P-supply levels, even when the P-supply was severely limiting P uptake. This reduction in P uptake at all P levels was equivalent to the reduction in water volume between the two water treatments, and is apparently a result of a lower supply of solution phosphate in the lower water treatment in the highly buffered soil.

DEVELOPMENTAL TIMES AND FECUNDITY OF IXODES COOKEI PACKARD (ACARI: IXODIDAE) UNDER LABORATORY CONDITIONS

1991 ◽  
Vol 123 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Martha J. Farkas ◽  
Gordon A. Surgeoner
Keyword(s):  
Relative Humidity ◽  
Blood Meal ◽  
Egg Development ◽  
Thermal Threshold ◽  
Egg Hatch ◽  
Marmota Monax ◽  
Complete Development ◽  
Laboratory Conditions ◽  
Adult Females ◽  
Blood Meal Source

AbstractIxodes cookei Packard required ca. 14 weeks to complete development under laboratory conditions, using groundhogs [Marmota monax (L.)] as the blood meal source and off-host conditions of 25–29°C and 93–100% relative humidity. All three post-embryonic instars engorged in ca. 6–8 days. Larvae and nymphs maintained at 25°C moulted to the next instar ca. 18–20 days after detachment. Moult occurred under conditions of either a 0L:24D or a 16L:8D photoperiod. Adult females increased in weight ca. 49-fold from the unfed to the engorged state, attaining a weight of 194.1 ± 15.0 (mean ± SE) mg and producing 1281.5 ± 139.1 (mean ± SE) eggs at 29°C. The pre-ovipositional and ovipositional periods were 4.7 ± 0.3 and 20.2 ± 1.7(mean ± SE) days, respectively, at 29°C. Fifty percent of eggs were deposited within the 1st week of the ovipositional period at 29°C. First egg hatch at 29°C occurred ca. 31 days after oviposition was started. Eggs maintained at 10°C did not hatch, and the thermal threshold for egg development was calculated to be 11.2°C.

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