scholarly journals Efficacy and temperature dependence of 60% and 85% formic acid treatment against Varroa destructor

Apidologie ◽  
2021 ◽  
Author(s):  
Xenia STEUBE ◽  
Patricia BEINERT ◽  
Wolfgang H. KIRCHNER

AbstractThe ectoparasitic mite Varroa destructor is considered one of the main threats to the western honey bee (Apis mellifera). Efficient pest management is crucial, and the evaporation of formic acid (FA) is an active principle that could be adopted. However, the usage of FA has an extreme variable efficacy depending on several conditions, ambient temperature among them. Cooler conditions, as they usually occur in Central Europe in late summer and autumn, can negatively affect treatment success. Our study aims to evaluate factors that influence the efficacy of different FA treatments. Over a period of 8 years, we investigated the effect of ambient temperature, hive size and dispenser type on the treatment success with 60% and 85% FA and consolidated those factors in a linear regression model. Treatment with 60% FA shows higher variability, and often lowered efficacy, especially in double brood chamber hives. In contrast, 85% FA treatment achieves higher efficacy and lower variability and shows significantly diminished dependence on ambient temperature.

2020 ◽  
Vol 57 (4) ◽  
pp. 1184-1192
Author(s):  
Allan T Showler ◽  
Bailee N Dorsey ◽  
Ryan M Caesar

Abstract Ixodids are blood-feeding ectoparasitic vectors of many disease agents that infect humans, livestock, and wild animals. As ixodid resistance to conventional synthetic acaricides becomes increasingly problematic, natural products are receiving greater attention as possible alternative control tactics. Formic acid, produced by ants, is a commercially available product for fumigating varroa mites, Varroa destructor Anderson & Trueman, infesting honey bee, Apis mellifera L., hives, and it has been reported to repel ixodids. Lone star tick, Amblyomma americanum (L.), larvae and nymphs were used as a model ixodid to investigate deterrent, repellent, and lethal effects of formic acid as a fumigant and contact toxin in vitro in the laboratory. Although formic acid failed to deter or repel A. americanum, it was highly toxic as a fumigant to larvae at a 1% concentration even when exposure was limited to 5 min. Contact by crawling on wet, moist, and dry treated substrates under ventilated conditions causes >90% mortality to larvae in 5% formic acid concentration treatments within 30–120 min, and temporary immersion killed ≈60% of the larvae by 24 h after they were removed from the 5% formic acid treatment solution. Substantial nymphal mortality occurred after 1–1.5 h following exposure to substrate treated with the 10% concentration and immersion killed ≈45% of the nymphs. It appears that formic acid volatiles are more lethal to A. americanum immatures than direct contact with the external integument.


2003 ◽  
Vol 135 (5) ◽  
pp. 749-763 ◽  
Author(s):  
P. Gatien ◽  
R.W. Currie

AbstractThe timing of acaracide treatments for control of low-level populations of Varroa destructor Anderson et Trueman has implications for colony performance of honey bees, Apis mellifera L. (Hymenoptera: Apidae). Replicated colonies with low levels of V. destructor were left untreated, exposed to fluvalinate at each of two doses for 42 days, or exposed to three applications of formic acid, with the four treatments applied in either spring or fall. Varroa destructor densities were measured by alcohol wash and drop boards, and both gave similar estimates. Over the course of one season, the mean abundance of V. destructor increased from 0.002 to 0.11 mites per bee. Extended broodless periods during winter reduced the mean abundance of V. destructor by 28%, but mite mortality over winter was not high enough to prevent the need for treatment the following year. Apistan® was more effective than formic acid in both spring and fall treatments. Doses of one or two strips of Apistan® per colony were equally effective in spring or fall treatments. The mean abundance of V. destructor remained low throughout the season following spring treatment with either dose of Apistan®. Fall formic-acid treatments were more effective than spring treatments. Fluvalinate residues in samples of honey and wax collected from brood chambers and from honey supers were slightly higher in colonies treated with two strips of Apistan® than with one strip, but no detectible residue was found in extracted honey from 4500 commercial colonies treated in spring with Apistan® one strip per brood chamber for single or double storey hives. The levels of V. destructor in this study did not affect honey production or colony survival over winter.


2011 ◽  
Vol 7 ◽  
pp. S140-S140
Author(s):  
Masahiro Koge ◽  
Ikuo Tooyama ◽  
Naoko Kameshima ◽  
Takaomi Fukuhara ◽  
Toshifumi Nanjo
Keyword(s):  

2018 ◽  
pp. 83-87
Author(s):  
Marianna Takács ◽  
János Oláh

An apiary trial was conducted in 2016 August to October in Szabolcs-Szatmár-Bereg County, Nyírmada to evaluate the influence of queen’s age on the Varroa destructor-burden in the treatment colonies. Sixty colonies of bees belonging to the subspecies Apis mellifera carnica pannonica in Hunor loading hives (with 10 frames in the brood chamber/deep super) were used. The colonies were treated with amitraz and the organophosphate pesticide coumaphos active ingredients. The amitraz treatment includes 6 weeks. The coumaphos treatment with Destructor 3.2% can be used for both diagnosis and treatment of Varroasis. For diagnosis, one treatment is sufficient. For control, two treatments at an interval of seven days are required. The colonies were grouped by the age of the queen: 20 colonies with one-year-old, 20 colonies with two-year-old and 20 colonies with three-year-old queen. The mite mortality of different groups was compared. The number of fallen mites was counted at the white bottom boards. The examination of spring growth of honey bee colonies has become necessary due to the judgement of efficiency of closing treatment. The data was recorded seven times between 16th March 2017 and 19th May 2017. Data on fallen mites were subjected to one-way analysis of variance (ANOVA) and Post-Hoc Tukey-test. Statistical analysis was performed using the software of IBM SPSS (version 21.). During the first two weeks after treatments, the number of fallen mites was significantly higher in the older queen’s colonies (Year 2014). The total mite mortality after amitraz treatment in the younger queen’s colonies was lower (P<0.05) compared to the three-year-old queen’s colonies. According to Takács and Oláh (2016) although the mitemortality tendency, after the coumaphos (closing) treatment in colonies which have Year 2014 queen showed the highest rate, considering the mite-burden the colonies belongs to the average infected category. The colonial maintenance ability of three-year-old queen cannot be judged based on the influencing effect on the mite-burden. The importance of the replacement of the queen was judged by the combined effect of several factors. During the spring-growth study (16th March–19th May) was experienced in the three-year-old queen’s colonies the number of brood frames significantly lower compared to the one- and two-year-old queen’s colonies. In the study of 17th April and 19th May each of the three queen-year-groups were varied. Therefore in the beekeeping season at different times were determined the colonial maintenance ability of queens by more factors: efficiency of closing treatment in early spring, the spring-growth of bee colonies, the time of population shift (in current study, this time was identical in each queen-year), honey production (from black locust).


Energy ◽  
1998 ◽  
Vol 23 (12) ◽  
pp. 1107-1112 ◽  
Author(s):  
Satoshi Kaneco ◽  
Ryosuke Iwao ◽  
Kenji Iiba ◽  
Kiyohisa Ohta ◽  
Takayuki Mizuno

1990 ◽  
Vol 51 (1) ◽  
pp. 1-13 ◽  
Author(s):  
C. S. Mayne

ABSTRACTHerbage from the first regrowth of perennial ryegrass based swards was direct-ensiled following treatment with either an inoculant of Lactobacillus plantarum (Ecosyl, Imperial Chemical Industries pic) at 3·0 1/t, formic acid (850 g/kg) at 2·9 1/t, or no additive (control). During harvesting, alternate loads of inoculant material were treated with an absorbent polymer (ammonium polyacrylamide) at the rate of 1 kg/t herbage and ensiled in separate 100-t capacity silos. The mean dry matter (DM) and water soluble carbohydrate concentrations of herbage used for the four treatments was 157 and 120 g/kg respectively. Lactic acid levels post ensiling increased more rapidly in inoculant-treated herbage than with the other treatments. Formic acid and inoculant-treated silages were well preserved whereas control and inoculant-plus-polymer silages were only moderately well preserved. Losses of DM during ensilage were greater with the formic acid treatment with DM recovery values of 0·78, 0·72, 0·76 and 0·73 for the control, formic acid, inoculant and inoculant-plus-polymer silages respectively. Treatment of herbage with an absorbent polymer prior to ensiling resulted in a proportional reduction in effluent volume of 0·2 whereas formic acid treatment increased effluent flow by 0·28. The silages were evaluated in a changeover design experiment with two periods each of 4 weeks duration, using 24 British Friesian dairy cows. Animals were housed in individual stalls and in addition to the treatment silages, received 5 kg/day of supplement containing 193 g crude protein per kg DM. Silage intakes were increased by proportionately 0·10, 0·14 and 0·05 respectively with the formic acid, inoculant and inoculant-plus-polymer treatments compared with the control. The increased silage intakes with the inoculant treatment were reflected in an increased milk yield of 1·1 kg milk per day whereas formic acid and inoculant-plus-polymer treatments had no significant effect, although formic acid treatment did result in a significant increase in milk fat concentration. There were no major differences between treatments in energy or nitrogen digestibility, when determined on a complete ration basis. In conclusion, a large milk yield response was obtained as a result of treatment of herbage with inoculant prior to ensiling and this resulted from increased silage and hence energy intake. Treatment with formic acid increased silage and energy intake but had no effect on milk energy output.


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