Mealybug Research Articles

Triple coitus in the mealy bug, Planococcus citri (Risso).

MALES of the mealy bug, Planococcus citri, do not feed throughout their nymphal stages of development nor after they emerge as adults. They are, nevertheless, highly active in mating during the few days of their short life as mature individuals. James1 has observed that a single male may copulate with as many as 23 females in succession, and the average number of females fertilized by 13 individual males was 9.07. During my experience with mealy bugs cultured in the laboratory on potato, the observation has been made many times that two males will copulate simultaneously with one female while yet a third male may be attempting to do the same.

Studies on breeding and control method of citrus ground mealy bug, Rhizoecus kondonis KUWANA

1. Using breeding veils for soil insect, the authors bred citrus ground mealy bugs to know their ecological characters, and investigated relationship between their density and the presence of straw mulch under mandarin orange trees at the damaged orchard, and also their resistibility against agricul-tural chemicals, to propose their effective control method suggested by results of these experiments. 2. The optimum margin of temperature and water content of saw-dust where the bug is bred (shown in percentage against water capacity) was found to range between 15_??_25°C of temperature and 27.6_??_52.5% water content, and its range was comparatively narrow. In case of wireworms (Melanotus caudex LEWIS) breeding, it ranged between 10_??_25°C of temperature and 27.6_??_89.4% of water content; in case of Japa-nese beetles (Popillia japonica NEWMAN) in larval stage, it was between 10_??_30°C of temperature and 19.1_??_93.1% of water content. The optimum temperature to breed citrus ground mealy bugs was the middle between both kinds of species, but the condition where water content of saw-dust is exceedingly less than in cases of both insects was suited to breeding of this one. 3. As water content of saw-dust increased the mortality of this insect increased, and in case of 100% water content no living insect completely existed in saw-dust; on the other side they came up to soil surface when the water content increased than 52.5%; and its tendency was remarkable as water content increased. 4. Because injurious insects died as water content increases, the authors investigated water content of soil under rotten straw mulch at damaged orchards. Water content of these soils showed nearly 100% even a few days after rainfall, which leads the authors to presume that the straw mulch over, the orchards is useful to control this insect. 5. Experiments on suspected relation between their density and the presence of straw mulch were carried out. In case of covering the whole orchards with straw mulch, the density of this insect was much less than that of no covering at the same damaged field; its damage was rather negligible. 6. In Fujieda district (Shizuoka Prefecture), damaged orchards were situated only at a slope land, and their management was bad: there was scarcely any cover of straw mulch, mandarin orange trees spread their shallow roots just under soil surface, and tea trees were planted under them. 7. The resistibility of this insect against agricultural chemicals was very weak; the insecticidual effects of calcium cyamide and tobacco dust were comparatively strong. 8. The authors suggest the following method for its successful controlling. After cleaning the soil surface of damaged orchards, and dusting with non-phytotoxicitic insecticide having a long residual-effect, the whole surface of orchards must be covered with thick straw mulch, because the insect con-cerned dies or comes up to the soil surface with increase in water content of soil.

Influence of Fertilizers on the Abundance of Pyrilla, Infesting Sugarcane

It is not always true that crops grown in soils with nutrients optimum for vigorous plant growth are able to with stand the attack. of insect pests better than the crops grown in deficient soils. Experimental facts are available where certain pests have shown a greater preference for crops having luxurient growth as a result of increased plant nutrients in the soil. Schoene (1941) showed that the injury to apple trees by the mealy bug, Pseudococcus comstockii Kuw., was most severe in orchards that had been treated with nitrogenous fertilizers for several years but no damage occurred on unfertilized trees. Gadd (1943) noted increased damage to tea plants by the borer, Xyleborus fornicatus Egg., following increased amounts of nitrogenous, phosphatic and potassium fertilizers. The results of the field experiments conducted by McGarr (1943) showed that the nitrogenous fertilizers caused a definite increase in the number of aphids, Aphis gossypii Glov,, on cotton. Eden (1953) found that the damage of the rice weevil on the maize in the field încreased with the addition of nitrogen in the soil. During the past several years it has been observed that pyrilla infestation was severe in sugarcane fields with higher level of manuring. Similar observations have also been made by Mathur and Gupta (1940) and Mathur (1941).

The Control of the Rice Mealy Bug-Ripersia Oryzae Gr-in the Tanjore Delta of the Madras State

Mealy bugs and scales are serious pets on culti- vated crops-The mealy bug Ripersia Oryzae Gris responsible for the malady popularly known as "soorai" on paddy in the Madras State. It is widely distributed in the Madras State and has been noted in Tanjore, South Arcot, Tiruchirappalli, Coimbatore, and Malabar districts. It occurs in a fairly severe form more often in the Tanjore delta than in other tracts.

A Note on the mealy Bug - Pseudococcus virgatus Cockerell, on Gliricidia maculata H & B and its Control

Mealy bugs belong to the family Coccidao' a category which includes some of the most serious pests of crops, ornamental plants and particularly of fruit trees also. As implied in the name, most of the species are provided with a mealy covering all over their body. The life history and habits in general are briefly as follows. The full grown females are mostly stationary, fixing themselves more or less permanently to their feeding spots on their host plants. The eggs are extruded below the body of the female. The uymphs hatch out in due course, crawl about upto a certain stage of their development and in their turn establish themselves in suitable parts. The adults and young are provided with needle-like mouth parts with which they pierce the plant tissue and suck up the juice. They occur in small groups or colonies, invariably on the tender and succulent shoots, but a good many forms are also found on other parts of the plants, like the stem, fruits, etc. The damage caused by the bugs is often serious, since the heavy drain on the coll sap would naturally reflect on the health of the host, if not kill it outright.

Insect Transmission of Cacao Virus Disease in Trinidad

Insect Transmission of Cacao Virus Disease in Trinidad

Entomological Aspects of ‘Swollen Shoot' of Cacao

THE rapid spread of the deadly ‘swollen shoot' disease of cacao first recorded by Steven1 in 1936 justly gives cause for alarm. Now believed to be due to a virus transmitted by three species of insects of the family Pseudococcidae, this malady of unknown origin bids fair to destroy the West African cacao industry. That this is realized by the people of West Africa is evident from the lively public interest in the problem.

Coccids attacking Cacao (Theobroma cacao, L.), in West Africa, with Descriptions of five new Species

Cacao was introduced into West Africa in the latter years of the last century and for a time remained relatively free from pests and diseases. It is, in fact, only recently that two major scourges have developed to a point where they are threatening the future of the cacao industry in the Gold Coast and Nigeria. The first, the cacao Mirids (Sahlbergella singularis, Hagl., andDistantiella theobroma, Dist.) is outside the range of the present paper. The second, and most important, is a virus disease, known as “Swollen Shoot”, which is transmitted from tree to tree by at least three species of mealybugs of the family Pseudococcidae.

A PRIMITIVE COCCID CHROMOSOME CYCLE IN PUTO SP

A primitive chromosomal cycle possibly archetypal for coccids is reported for Puto sp. of the family Pseudococcidae. There is no hermaphroditism nor any cytological evidence for parthenogenesis. The diploid chromosome number is 14 in the female, 13 in the male. Somatic mitosis is of the type characteristic for chromosomes with diffuse kinetochore. Meiosis is regular in both sexes. In the male it can be demonstrated to adhere to the coccid-aphid type, with: (a) the first division equational for non-crossover regions; (b) separation of chromatids and their secondary pairing during interkinesis, and (c) segregation of non-crossover regions in the second division. An XX -female, XO -male sex determining mechanism is present. Quadrinucleate spermatids are formed. This is the only coccid thus far reported with a simple and orthodox meiosis in both sexes.

A new Mealy Bug attacking Pineapple Plants in Mauritius

The pineapple plantations of Mauritius have sustained since 1937 severe attacks of mealybugs (Pseudococcus spp.) which threatened to ruin the whole crop in certain localities. These attacks result in a wilting of the plants, which may be due to a toxin secreted by the bugs during their process of feeding.

Comstock's Mealy bug on Apple and Catalpa

Journal Article Comstock's Mealy bug on Apple and Catalpa Get access James A. Cox James A. Cox Virginia Agricultural Experiment Station, Blackburg Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 33, Issue 3, 1 June 1940, Pages 445–447, https://doi.org/10.1093/jee/33.3.445 Published: 01 June 1940

THE LIFE HISTORY OF ALLOTROPA UTILIS MUES., A HYMENOPTEROUS PARASITE OF THE ORCHARD MEALY BUG IN NOVA SCOTIA

Soon after the discovery of the mealy bug Phenacoccus aceris Sig. in the orchards of Nova Scotia in 1932, a parasite of much importance was found attacking this pest. This is a small hymenopterous species described in this issue by Dr. C. F. W. Muesebeck as a new species, Allotropa utilis Mues.

OBSERVATIONS ON THE MEALY BUG, PHENATACOCCUS ACERIS SIG.

In the Canadian Entomologist, August, 1935, the writer presented a short life-history of the mealy bug, Phenacoccus aceris Sig. Since the preparation of the above paper, further interesting observations have been recorded.The female nymphs emerge from the winter cocoons and disseminate over the tree to feed, considerably earlier in the spring than was originally suppsed. When visiting an infested orchard near -Annapolis Royal on March 20, 1935, the writer was surprised to find that the females were already feeding in small numbers on the fruit spurs. An estimate of the emergence at this date was from 4 to 5 percent of the total infestation. A few were also observed emerging from the winter cocoons and beginning to make their way to the outer limbs. These observations were made on a clear bright day about 4 p.m. At the time, it was slightly below freezing in the shade. In the sunshine the temperature was probably a few degrees above the freezing point. There was nearly a foot of snow under the trees in the orchard.

A MEALY BUG, PHENACOCCUS ACERIS SIGNORET, A NEW APPLE PEST IN NOVA SCOTIA

During 1932 a species of mealy bug came into prominence in a few orchards in the Annapolis valley, more particularly at Lakeville and the district north of Berwick. The insect was less conspicuous in 1933, but in 1934 some severe infestations occurred. This mealy bug is scattered over the entire fruit growing area in Nova Scotia, and has probably been present for several years.

Further Experiments on Organic Thiocyanates as Insecticides

Five closely related organic thiocyanates were synthesized and their insecticidal properties compared with that of γ -thiocyanoproyl phenyl ether, previously tested. Of these compounds one, namely, trimethylene dithiocyanate, was definitely superior to the above mentioned ether, while the remainder were distinctly inferior. Trimethylene dithiocyanate was considerably more toxic than its isomer, propylene dithiocyanate. Trimethylene dithiocyanate gave satisfactory control in laboratory tests on APhis rumicis, the melon aphid (Aphis gossypii), the citrus mealy bug (pseudococcus citri), the long-tailed mealy bug (Pseudococcus adonidum), the lesser European bark beetle (Scolytus multistriatus), the potato flea beetle (Epitrix cucumeris), and the red spider mite (Tetranychus telarius). Of 75 species and varieties of plants tested with regard to their tolerance to trimethylene dithiocyanate (0.1 per cent) 64 were tolerant as compared with 59 for γ -thiocyanopropyl phenyl ether used at the same concentration.

Control of Mealy Bugs and Other resistant Insects on Hardy Plants With a Completely Refined Petroleum Distillate*

Control of Mealy Bugs and Other resistant Insects on Hardy Plants With a Completely Refined Petroleum Distillate*

THE PINEAPPLE BUD MOTHS IN HAWAII

Summary The two most important species of bud moth, in Oahu are Pyro‐derces rileyi Wlsm. and Ereunetis flavistriata Wlsm. Both species are evenly distributed over the island, the latter being the more common. They are most numerous in old ratoon fields, where they feed on dead plant tissue. They are also often found on young fruits, where, contrary to certain claims, they appear to do very little damage. Methods of distribution are discussed; wind is probably the most important factor. Although often found with mealy bugs, neither species appears to be predacious. Except when disturbed, the larvae are not molested by ants, but when unfavourable circumstances cause them to wander, large numbers may be killed in this way. Parasitism is very low. Only two parasites have been reared from several hundred larvae. Predators, principally Sphecoid wasps, carry off many larvae, but being unable to reach the majority are relatively ineffective as a means of control. Apart from the regular spraying for control of mealy bugs and the knocking down of old ratoon fields, no specific control measures are practised against bud moths, and any further effort would appear to be unwarranted.

Border Plantings as Guard Rows in Pineapple Mealy Bug Control1

The planting of several beds of pineapple plants in a strip parallel to the edge of fields and separated from the main plantation by a road is proving essential to economical spraying against Pseudococcus brevipes Ckl. These borders serve as guard rows against too rapid a movement of mealy bugs into the field and at the same time localize the area to be regularly sprayed.

Preliminary Report on Evidence That Mealy Bugs are an Important Factor in Pineapple Wilt

This paper summarizes results covering a period of four years in Hawaii. Evidence is presented indicating that Pineapple Wilt is a disease, transmitted by the pineapple mealy bug ( Pseudococcus brevipes , Ckll.), and that infection only takes place after the insects have fed upon diseased plants. The tremendous economic importance of the problem is gone into; and the interrelation with ants fully considered. Tentative methods of dealing with these pests are suggested, and the further introduction of natural enemies, particularly parasites, recommended.

LVI.—Two new mealy bugs from India

LVI.—<i>Two new mealy bugs from India</i>